Solve the equation by completing the square. x2 + 16x = 7

x = + , -

x ≈ .426, -16.426

Step-by-step explanation:

When we complete the square, we add a value to both sides to make the left side a "perfect square" that we can simplify to (a+b)^2.

x^2 + 16x = 7

x^2 + 16x + _____ = 7 + ______

What do we put in the blank? The formula is to take half of b, then square that. Half of 16 is 8, 8^2 is 64, so

x^2 + 16x + 64 = 7 + 64

Now on the left side we have a perfect square!

(x+8)^2 = 71

Now all that's left to do is simplify this to get x. First take the square root of both sides.

x+8 =

x = + , -

x ≈ .426, -16.426

-3(b-8)-5=9(b+2)+1

distribute

-3b+24-5=9b+18+1

add/ subtract

-3b+20=9b+19

20-19= 1

-3b+1=9b

9b+3b= 12b

1=12b

1 divided by 12 = 1/12

answer: 1/12 = b

the angles measure to 70 degrees, 70 degrees, 20 degrees, and 20 degrees