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# Solving system of equation with elimination and substitution help.

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4. Solve the following system of equations:

3 + 2x - y = 0,

-3 - 7y = 10x

by using substitution, and by elimination.

Feb 24, 2019

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$$2x - y = -3\\ 10x+7y = -3$$

$$\text{substitution}\\ y = 2x+3\\ 10x+7(2x+3) = -3\\ 24x+ 21=-3\\ 24x=-24\\ x=-1, y = 1\\ --\\ \text{elimination}\\ \text{subtract 5x the first equation from the second}\\ 12y=12\\ y=1,~x=-1$$

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Feb 24, 2019

#1
+5766
+1
$$2x - y = -3\\ 10x+7y = -3$$
$$\text{substitution}\\ y = 2x+3\\ 10x+7(2x+3) = -3\\ 24x+ 21=-3\\ 24x=-24\\ x=-1, y = 1\\ --\\ \text{elimination}\\ \text{subtract 5x the first equation from the second}\\ 12y=12\\ y=1,~x=-1$$