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3 votes
HELP ME DO THIS
y=2x+4
-5x-5y=-5

User Marcela
by
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2 Answers

2 votes
y=2x+4
-5x-5y=-5
subsitute 2x+4 for y
-5x-5(2x+4)=-5
-5x-10x-20=-5
-15x-20=-5
add 20 to both sdies
-15x=15
divide by -15
x=-1

subsitute
y=2(-1)+4
y=-2+4
y=2


x=-1
y=2
User Crecket
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4 votes

\left \{ {{y=2x+4} \atop {-5x-5y=-5}} \right. \\\\ substitute\ first\ equation\ into \ the\ second\\\\ -5x-5(2x+4)=-5\\\\ -5x-10x-20=-5\\\\ -15x-20=-5\ \ \ | add\ 20\\\\ -15x=15\ \ \ | divide\ by\ -15\\\\ x=-1\\\\ y=2*(-1)+4=-2+4=2
User Fyrkov
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7.3k points