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3 years ago

What are the methods of substitution?

Mathematics

1 answer:

anyanavicka [17]3 years ago

8 0

Answer:

-One Equation: is set equal to a variable

Example:

y = 2x + 1

x + 3y = -12

You already have y, plug it back into x + 3y = -12

x + 3(2x + 1) = -12

x + 6x + 3 = -12

7x + 3 = -12

(Subtract 3 from each side)

7x = -15

(Divide by 7)

x = - 2.14

-No Equation: is set equal to a variable

Example:

2x + y = 10

4× + 2y = -3

Subtract 2x from each side of 2x + y = 10, you should get y= -2x + 10. Now that you have found y, substitute y into 4x+ 2y = -3.

4x + 2(-2x + 10) = -3

4x + -4x + 20 = -3

(Subtract 20 from each side)

4x + -4x = -23

(Add 4x and -4x)

0 = -23

No Solution

-Both Equations: are set equal to a variable

Example:

y = x + 5

y = -x + 3

(you already have y so plug it into the other equation to solve for x)

-x + 3 = x + 5

(Add -x on both sides)

3 = 2x + 5

(subtract 5 from both sides)

-2 = 2x

(Divide by 2 on each side)

x = -1

I hope this helped!

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Mrs. Oliver drew a box plot to represent her students’ scores on a mid-term test.

Rzqust [24]

Answer:

About 1/4 scored higher and 3/4 scored lower

Step-by-step explanation:

84 is on the right side line

Each line represents 25 % of the score

It is 75 percent ( 3 lines) of the way

She scored higher than 75% of the students and lower than 25% of the students

About 1/4 scored higher and 3/4 scored lower

6 0

1 year ago

-/2 points

Rom4ik [11]

Answer:

Part 1) The domain of the quadratic function is the interval (-∞,∞)

Part 2) The range is the interval (-∞,1]

Step-by-step explanation:

we have

$f(x)=-x^2+14x-48$

This is a quadratic equation (vertical parabola) open downward (the leading coefficient is negative)

step 1

Find the domain

The domain of a function is the set of all possible values of x

The domain of the quadratic function is the interval

(-∞,∞)

All real numbers

step 2

Find the range

The range of a function is the complete set of all possible resulting values of y, after we have substituted the domain.

we have a vertical parabola open downward

The vertex is a maximum

Let

(h,k) the vertex of the parabola

The range is the interval

(-∞,k]

Find the vertex

$f(x)=-x^2+14x-48$

Factor -1 the leading coefficient

$f(x)=-(x^2-14x)-48$

Complete the square

$f(x)=-(x^2-14x+49)-48+49$

$f(x)=-(x^2-14x+49)+1$

Rewrite as perfect squares

$f(x)=-(x-7)^2+1$

The vertex is the point (7,1)

therefore

The range is the interval

(-∞,1]

6 0

3 years ago

Please help! Question above

frez [133]

Answer:

It's the first one. (m + n - 1) sqrt p

Step-by-step explanation:

We can combine m sqrt p and n sqrt p, resulting in m + n, and combine - sqrt p to become (m + n - 1)sqrt p

3 0

3 years ago

The density of oxygen is 0.001429 grams per cubic centimeter. How is this number written in

Anika [276]

We have been given that the density of oxygen is 0.001429 grams per cubic centimeter. We are asked to write the given number in scientific notation.

To convert a number into scientific notation, we write the given number as product of two numbers. One factor is a number between 1 and 10, while the 2nd factor is power of 10.

When a decimal is to the left of given number, then we need to move the decimal to right such that the number gets between 1 and 10. Then, we multiply the number by negative power of 10 that many times, we moved the decimal to right.

We can see that decimal is to left of our number. To place decimal after 1, we have to multiply 10 to 3 times. To keep the value of number same we will multiply the same negative power (negative 3).

$0.001429\times 10^3\times 10^{-3}$