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3 years ago

Solve each system by subtracting

Mathematics

1 answer:

otez555 [7]3 years ago

7 0

What systems are you talking about?

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I don’t know any of these lol

neonofarm [45]

In this exercise, we want to know the x-intercepts of each item. To find the x-intercepts, set y = 0 as indicated in each item and solve for x. So:

<h2>1. Answer:</h2>

B. x=-1; x=-1.75

<h3>Step by step explanation:</h3>

we have the equation:

$4x^2+11x+7=0$

We can say that this equation comes from the function $f(x)=4x^2+11x+7$ so we have set $y=0$ to find the x-intercepts. By using the quadratic formula we have:

$x=\frac{-b \pm \sqrt{b^2-4ac}}{2a} \\ \\ where: \\ \\ a=4, \ b=11, \ c=7 \\ \\ x=\frac{-11 \pm \sqrt{11^2-4(4)(7)}}{2(4)} \\ \\ x=\frac{-11 \pm \sqrt{121-112}}{8} \\ \\ \boxed{x_{1}=-1 \ and \ x_{2}=-1.75}$

<h2>2. Answer:</h2>

B. x=-1; x=-1.75

<h3>Step by step explanation:</h3>

we have the equation:

$3x^2-4x+1=0$

We can establish a function $g(x)=3x^2-4x+1$ and say that we want to find the x-intercepts of this function by setting y = 0. Therefore, by using the quadratic formula we have:

$a=3, \ b=-4, \ c=1 \\ \\ x=\frac{-(-4) \pm \sqrt{(-4)^2-4(3)(1)}}{2(3)} \\ \\ x=\frac{4 \pm \sqrt{16-12}}{6} \\ \\ \boxed{x_{1}=1 \ and \ x_{2}=\frac{1}{3}}$

<h2>3. Answer:</h2>

H. No Solution

<h3>Step by step explanation:</h3>

we have the equation:

$3x^2-4x+2=0$

We can establish a function $h(x)=3x^2-4x+2$ and say that we want to find the x-intercepts of this function by setting y = 0. Therefore, by using the quadratic formula we have:

$a=3, \ b=-4, \ c=2 \\ \\ x=\frac{-(-4) \pm \sqrt{(-4)^2-4(3)(2)}}{2(3)} \\ \\ x=\frac{4 \pm \sqrt{16-24}}{6}$

Since 16 - 24 = -8, that is, a number less than zero which is within a square root, we say that the equation $3x^2-4x+2=0$ has no any real solution.

<h2>4. Answer:</h2>

E. x=1

<h3>Step by step explanation:</h3>

we have the equation:

$x^2-2x+1=0$

We can establish a function $c(x)=x^2-2x+1$ . By setting y = 0 we'll find the x-intercepts. Let's solve this problem using other method. You can find some binomial products having a special form. So it's easier to find a solution by using distributive. The form of this polynomial is a Square of a Binomial in the form:

$(x-1)^2=0 \\ \\ Because: \\ \\ (x-1)^2=(x-1)(x-1)=x^2-x-x+1= x^2-2x+1$

Therefore, the value that satisfies this equation is $\boxed{x=1}$

<h2>5. Answer:</h2>

K. x = -1

<h3>Step by step explanation:</h3>

we have the equation:

$x^2+2x+1=0$

We can establish a function $a(x)=x^2+2x+1$ . By setting y = 0 we'll find the x-intercepts. We are going to solve this problem by using the previous method. The form of this Square of a Binomial is:

$(x+1)^2=0 \\ \\ Because: \\ \\ (x+1)^2=(x+1)(x+1)=x^2+x+x+1= x^2+2x+1$

Therefore, the value that satisfies this equation is $\boxed{x=-1}$

<h2>6. Answer:</h2>

N) x = 1/2

<h3>Step by step explanation:</h3>

we have the equation:

$4x^2-4x+1=0$

We can establish a function $b(x)=4x^2-4x+1$ and say that we want to find the x-intercepts of this function by setting y = 0. Here we will use the quadratic formula, so:

$a=4, \ b=-4, \ c=1 \\ \\ x=\frac{-(-4) \pm \sqrt{(-4)^2-4(4)(1)}}{2(4)} \\ \\ x=\frac{4 \pm \sqrt{16-16}}{8} \\ \\ \boxed{x=\frac{1}{2}}$

So we have just one solution.

<h2>7. Answer:</h2>

M) x = -1/2

<h3>Step by step explanation:</h3>

we have the equation:

$4x^2+4x+1=0$

We can establish a function $b(x)=4x^2+4x+1$ and say that we want to find the x-intercepts of this function by setting y = 0. As in the previous exercise, we will use the quadratic formula, so:

$a=4, \ b=4, \ c=1 \\ \\ x=\frac{-4 \pm \sqrt{(4)^2-4(4)(1)}}{2(4)} \\ \\ x=\frac{-4 \pm \sqrt{16-16}}{8} \\ \\ \boxed{x=-\frac{1}{2}}$

So we have just one solution.

<h2>8. Answer:</h2>

D) x = -1.45; x=1.25

<h3>Step by step explanation:</h3>

we have the equation:

$5x^2+x-9=0$

We can establish a function $D(x)=5x^2+x-9$ and say that we want to find the x-intercepts of this function by setting y = 0. By using the quadratic formula we can solve this problem, so:

$a=5, \ b=1, \ c=-9 \\ \\ x=\frac{-1 \pm \sqrt{(1)^2-4(5)(-9)}}{2(5)} \\ \\ x=\frac{-1 \pm \sqrt{1+180}}{10} \\ \\ \boxed{x_{1}=-1.45 \ and \ x_{2}=1.25}$

<h2>9. Answer:</h2>

J) x = 4; x=-3

<h3>Step by step explanation:</h3>

we have the equation:

$-x^2+x+12=0$

We can establish a function $k(x)=-(x^2-x-12)$ and say that we want to find the x-intercepts of this function by setting y = 0. In this exercise we'll use other method. Since this is a non-perfect square trinomial, we know that:

$(x+a)(x+b)=x^2+(a+b)x+ab$

So let's find two numbers such that the sum is -1 and the product is -12. Those numbers are -4 and 3, thus:

$-(x-4)(x+3)=-x^2+x+12=0$

Therefore, our solutions are:

$x=4 \ and \ x=-3$

________________

<h3>THE OTHER SOLUTIONS HAVE BEEN ATTACHED BELOW</h3>

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6 0

3 years ago

Read 2 more answers

The number of movies watched by several students in the last month is shown in the list.

andrew-mc [135]

Answer:

Plot number 2

Step-by-step explanation:

5 0

3 years ago

A group of Republicans and Democrats was surveyed and each member was asked whether they liked apple pies or eclairs. 80% of the

kirill [66]

Answer:

Any multiple of 71 (i.e. 71, 142, 710, etc)

Step-by-step explanation:

Republicans = R

Democrats = D

Republicans that liked apple pie = 0.80R

Democrats liked eclairs = 0.55D

Republicans who liked apple pie that also liked eclairs = (0.80*0.20)R

If the number of Republicans who liked both desserts is equal to the number of Democrats who liked eclairs, then the following must be true:

$(0.8*0.2)R=0.55D\\0.16R=0.55D\\16R=55D$

Since the number of Republicans and Democrats must be integers, the least number of members possible is 71 (55+16).

Any value that is a multiple of 71 is a possible value for the number of members of the group

3 0

4 years ago

The number five added to the product of 8 and -9 is what number?<br><br> The number is___

Nataly_w [17]

Answer:

-67

Step-by-step explanation:

8 x -9 = -72 + 5 = -67

6 0

3 years ago

Read 2 more answers

A trade magazine routinely checks the drive-through service times of fast-food restaurants. Upper AA 9595% confidence interva

exis [7]

Answer:

The statement describes that:

A person can be 9595 percent sure that the mean drive through service period of this chain is between 164.5164.5 seconds and 168.3168.3 seconds.

8 0

4 years ago