I NEED THE ANSWER ASAP Find the solution to the following system by substitution.

2x + y = 20
y = 2x

A. (10,0)
B. (0,20)
C. (5, 10)
D. (10, 20)

0if x and y vary inversely and y=6 as x=7, what is the constant of variation?

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x

What is the distance between a and b? round your answer to the nearest tenth. a coordinate plane is shown. point a is located at negative 1, 5, and point b is located at 4, 1. a line segment connects the two points.