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3 years ago

how to solve quations using subsitution. The equation I need to solve is 2x+y=5 -3x+2y=17 please explain it in detail thank you

1 answer:

3 0

We have a system of 2 linear equations with 2 unknown, so we can solve it:
 2x + y = 5
-3x + 2y = 17
We'll use substitution, so lets solve for y in the first equation and substitute that in the second afterwards:
y = 5 - 2x
-3x + 2(5 - 2x) = 17
-3x + 10 - 4x = 17
-7x = 7
x = -1
then substitute in the original equation to find y:
y = 5 - 2x = 5 - 2(-1)
= 5 + 2
y = 7

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simplify by dividing firs equation by 2 and 2nd by 4

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multiply first equaiton by -3 and add to second
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