## Algebra: A Combined Approach (4th Edition)

True for all values of $x$ and $y$.
equation 1 $$0.6x - 0.3y = -1.5$$ equation 2 $$0.04x - 0.02y = -0.1$$ Multiply equation 1 by $-0.04$ and equation 2 by $0.6$ equation 1 $$[0.6x - 0.3y = -1.5]\cdot-0.04$$ $$-0.024x+0.012y=0.06$$ equation 2 $$[0.04x - 0.02y = -0.1]\cdot0.6$$ $$0.024x-0.012y=0.06$$ Add both equations: $$-0.024x+0.012y=0.06$$ $$0.024x-0.012y=0.06$$ $$0=0$$ Thus, the system is true for all values of $x$ and $y$.