All categories

3 years ago

Josephine solved a quadratic equation. Her work is shown below.

Mathematics

1 answer:

mariarad [96]3 years ago

7 0

Answer:

Step-by-step explanation:

hello :

5(x + 7)² = 245

(x + 7)² = 49

x=0 is solution but you have other solution -14 because :(-14+7)² = (-7)² =49

here is an solution Step-by-step :

(x + 7)² = 49 means : (x + 7)² = 7²

(x + 7)² - 7²=0 use identity : a²-b² = (a-b)(a+b)

a=x+7 and b= 7

(x+7-7)(x+7+7) = 0

x(x+14)=0

x=0 or x+14=0

so : x=0 or x= -14

You might be interested in

Probability With a Pair of Dice: Find the probability of rolling the difference of 1.

ra1l [238]

Answer:

there are 10 possibilities out of 36, which is 27.8%, or a chance of 1 in 3.6

Step-by-step explanation:

5 0

3 years ago

Help pls pls pls<br><br> 4 x 10<br> plssss plz plz plzz so hard

mrs_skeptik [129]

Answer:

Step-by-step explanation:

4 x 10= 40

PlZ add brainliest.

8 0

3 years ago

Read 2 more answers

Simplify.<br> -5x^4(-3x^2+4x-2)

dybincka [34]

Simplification/ 15x^6-20x^5+10x^4

7 0

3 years ago

Explain how to solve 2(x-1)=-200

Mamont248 [21]

I attached the answer below. Please take a look. You're welcome.

3 0

3 years ago

Solve the system of linear equations for x and y.(cos θ)x + (sin θ)y=1(−sin θ)x + (cos θ)y = 0x=y=

lys-0071 [83]

Answer:

$\bold{x =cos\theta}\\\bold{y=sin\theta}$

Step-by-step explanation:

The given system of linear equations is:

$(cos\theta)x+(sin\theta)y=1\\(-sin\theta)x+(cos\theta)y=0$

We have to solve the equations for the values of $x, y$ .

Let us use elimination method in which we eliminate one of the variables from the two variables.

For this, let us multiply the first equation by $sin\theta$ and second equation by $cos\theta$

Now, the equations become:

$(cos\theta.sin\theta)x+(sin\theta.sin\theta)y=sin\theta\\\Rightarrow (cos\theta.sin\theta)x+(sin^2\theta)y=sin\theta ....... (1)\\\\(-sin\theta.cos\theta)x+(cos\theta.cos\theta)y=0\\\Rightarrow (-sin\theta.cos\theta)x+(cos^2\theta)y=0 ..... (2)$

Now, let us add (1) and (2):

$(sin^2\theta)y+(cos^2\theta)y=sin\theta\\\Rightarrow (sin^2\theta+cos^2\theta)y=sin\theta\\\Rightarrow (1)y=sin\theta\\\Rightarrow y = sin\theta$

Using the equation:

$(-sin\theta)x+(cos\theta)y=0$

Putting value of $y$ :

$\Rightarrow (-sin\theta)x+(cos\theta)sin\theta=0\\\Rightarrow (sin\theta)x=(cos\theta)sin\theta\\\Rightarrow x = cos\theta$

So, the answer to the system of linear equations is:

$\bold{x =cos\theta}\\\bold{y=sin\theta}$

7 0

2 years ago