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.