Answer:
Only choices C and D are solutions
Explanation:
6x + 3y = -15
y = -2x - 5
6x + 3y = -15
6x + 3(-2x - 5) = -15
6x - 6x - 15 = -15
0 = 0
Since 0 = 0 is a true statement, both equations of this system are the same equation and represent a single line on the coordinate plane.
We need to check each choice in just one equation.
Let's use the second equation.
y = -2x - 5
A.
(2, 7)
7 = -2(2) - 5
7 = -4 - 5
7 = -9 False
Not a solution
B.
(5, 0)
0 = -2(5) - 5
0 = -10 - 5
0 = -15 False
Not a solution
C.
(-3, 1)
1 = -2(-3) - 5
1 = 6 - 5
1 = 1 True
Solution
D.
-13 = -2(4) - 5
-13 = -8 - 5
-13 = -13 True
Solution
Answer: Only choices C and D are solutions