Answer:
x = -4
Step-by-step explanation:
2x² + 8x = x² - 16
x² + 8x + 16 = 0
x² + 4x + 4x + 16 = 0
x(x + 4) + 4(x + 4) = 0
(x + 4)² = 0
x = -4
Add 5 to both sides of the equation.
x=-14+5
Add -14 and 5.
x=-9
Consider the right triangle ABC with legs AB=4, AC=3 and hypotenuse BC=5. Angle B has

and

.
Since O lies in second quadrant

and

.
Answer:
.
The 3 inside angles of a triangle equal 180.
Add the 3 angles together to equal 180:
X + (5x-20) + 4x = 180
Simplify the left side by adding like terms:
10x-20 = 180
Add 20 to each side:
10x = 200
Divide both sides by 10:
x = 20
Angle A = x = 20
Angle B = 4X = 4(20) = 80
Angle C = 5x-20 = 5(20) -20 = 100-20 = 80
Y= -1x + -1 is the answer