Question

Tyson began solving the system ​ {4x+2y=64x+5y=15 ​ by writing −3y=−9 .

Which property justifies this step?

division property of equality
multiplication property of equality
substitution property of equality
subtraction property of equality

Answer 1

subtraction property of equality

Explanation:

...

Answer 2

4x+2y=6 (1)
4x+5y=15 (2)

1) - (2) =4x-x4 +2y -5y = 6 - 15
equivalent to -3y= -9
so the true answer is subtraction property of equality