Question

Which of the following are solutions to the system
{5x−2y=10−2.5x+y=−5? Select two answers.

A. (2,0)
B. (−2,−10)
C. (2,−5)
D. (−2,5)
E. (0, 2)

my first answer is c but im having trouble with finding the second answer :/

Answer 1

The two equations are really the same line.
So, just pick any x (or y) and find the corresponding y (or x).
C is certainly wrong, since 5(2) - 2(-5) = 10+10 = 20 ≠ 10

A: y=0, so 5x=10 ==> x=2
Note that if y in(de)creases by 5, x in(de)creases by 2.
So, if x=0, y=-5
try decreasing x by another 2 and see what you get.