Answer
$$x=\frac{3}{2}$$ $$y=-3$$
Work Step by Step
Equation 1: $y = -2x$
Equation 2: $4x + 7y = -15$
Substitute equation 1 to equation 2:
$$4x + 7(-2x) = -15$$ $$4x -14x = -15$$ $$-10x=-15$$
Divide both sides by $-10$:
$$\frac{-10x}{-10}=\frac{-15}{-10}$$ $$x=\frac{3}{2}$$
Substitute this value of $x$ to equation 1:
$$y=-2(\frac{3}{2})$$ $$y=\frac{-6}{2}$$ $$y=-3$$
Use equation 2 to check:
$$4(\frac{3}{2})+7(-3)=-15$$ $$6-21=-15$$ $$-15=-15$$