Question

Which choice is the most efficient first step to solve this set of equations?

y = 2x + 4
3x + 4y = 17

Answer 1

3x+4(2x+4)=17

Substitute (2x+4) for y in the second equation

Explanation:

Answer 2

Substitution is the most efficient.

Explanation:

Because the equation y = 2x + 4 already equates to y, one can easily substitute its expression 2x+4 into 3x + 4(y) = 17 where y is.

3x + 4(y) = 17

3x + 4(2x + 4 ) = 17