We'll use Cramer's rule for 2 equations:
ax + by = e
cx + dy = f
5x -3y = 18 a=5 b=-3 e=18
2x + 7y = -1 c=2 d=7 f=-1
denominator determinant (dn) = (a * d) - (c * b) = 5 * 7 - (2 * -3) = 41
x = [(e * d) - (f * b)] / dn
[18 * 7 - (-1 * -3)] / 41 =
123 / 41 = 3
y = [(a * f) - (c * e)] / dn
= (5 * -1) -(2 * 18) / 41 =
-41 / 41 = -1
Source:
1728.com/cramer.htm
Answer:
<h2>
45</h2>
Step-by-step explanation:

So, if the common ratio is 5 the next term is always 5 times the previous term.
<h3>9·5 = 45</h3>
Top triangle: if the know angle measures are 90 and 55 and there are a total of 180, 90 + 55 + a = 180. This means that angle a = 35°
Bottom triangle: if a is 35, the angle connected to it is 35 because they are vertical angles. The angles of this triangle are 35 + 120 + b = 180. Angle b = 25°
G(x) = (x+4)^4 is the answer. It's D. last choice
G(x) = (x+4)^4 shifted F(x) = x^4 4 units to the left