It's 75. After you wrote down all the possibilities for what G could be, just find the one that has a combination of numbers that add up to 12. 75 is 7+5=12

3 0

2 years ago

Solve for w, where w is a real number.

Ber [7]

Answer:

w= 9

Step-by-step explanation:

$\sqrt{ - 4w + 61} = w - 4$

Square both sides:

-4w +61= (w -4)²

$\boxed{(a - b)^{2} = a^2 -2ab + b^2 }$

Expand:

-4w +61= w² -2(w)(4) +4²

-4w +61= w² -8w +16

Simplify:

w² -8w +16 +4w -61= 0

w² -4w -45= 0

Factorize:

(w -9)(w +5)= 0

w -9= 0 or w +5= 0

w= 9 or w= -5 (reject)

Note:

-5 is rejected since we are only taking the positive value of the square root here. If the negative square root is taken into consideration, then w= -5 would give us -9 on both sides of the equation.

Why do we use negative square root?

When solving an equation such as x²= 4,

we have to consider than squaring any number removes the negative sign i.e., the result of a squared number is always positive.

In the case of x²= 4, x can be 2 or -2. Thus, whenever we introduce a square root, a '±' must be used.

However, back to our question, we did not introduce the square root so we should not consider the negative square root value.

6 0

1 year ago

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