Question

For the system of equations shown, tell whether it would take fewer steps to solve by substitution or elimination. Then use that strategy to solve the system. Explain your reasoning.

-3x - 4y = 15
9x + 7y = 25

Answer 1

Explanation:

Step: Solve−3x−4y=15for x:

−3x−4y=15

−3x−4y+4y=15+4y(Add 4y to both sides)

−3x=4y+15

−3x

−3

=

4y+15

−3

(Divide both sides by -3)

x=

−4

3

y−5