Step-by-step explanation:
2x + 100 = 90
x = -5
Angle A = 45 - 5 = 40.
Answer:
45 cm
Step-by-step explanation:

The answer is 2. I hope this helped.
Ok, so the quadratic coefient is 1, so great
take 1/2 of the linear coefient and square it
10/2=5, (5)^2=25
add that to both sides
x^2+10x+25=7+25
factor perfect square trionomial
(x+5)^2=32
squaer root both sides
x+5=+/-4√2
minus 5
x=-5+/-4√2
x=-5+4√2 and -5-4√2
Y = kx where k is a constant
27 = k*9
k = 27/9 = 3
required variation is y = 3x