How do you solve by substitution #y=-4x+8# and #y=x+7#?

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Answer 1 · 2018-03-26T20:26:17

#x = 1/5#

You have 2 expressions for y. #y = -4x + 8 and y = x+7#.

The second expression tells us that y is equal to #x+7#. Let's substitute #x+7# for the y in the first expression. That will give us

#x+7 = -4x + 8#

And now, let's simplify.

#x+4x = 8 - 7#

#5x = 1#

Therefore, #x = 1/5#.

I hope this helps,
Steve