5. Which would be a good first step to use to solve this system?



1st equation: y = 6x + 4

2nd equation: 5x + 2y = 12



A. Multiply the first equation by 2, and add the result to the second equation.

B. Substitute 5x + 12 for for y in first equation.

C. Substitute 6x + 4 for x in the second equation.

D. Substitute 6x + 4 for y in the second equation.