Question 20479
Given equations are:
3x + 4y = -5 --------> (1)

5x + 6y = -7 --------> (2)

Multiply eqn (1) by 5, 15x + 20y = -25 ------->(3)

Multiply eqn (2) by 3, 15x + 18y = -21 ------->(4)
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Subtract (4) from (3),        2y = -4

y = -2.
Plug y = -2 in eqn (1), we have 3x + 4(-2) = -5

3x=-5+8=3,   x = 1.

The solution of the equations are x=1 and y=-2.