SOLUTION: Solve by substitution method 15x-10y=-1 5y=1+10x

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Question 190154: Solve by substitution method
15x-10y=-1
5y=1+10x
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!


Given Line Eqns.
15x-10y=-1+, +%28red%28EQN1%29%29
5y=1%2B10x, %28red%28EQN2%29%29


In EQN 2, isolate "y" then subst. value to red%28EQN1%29
cross%285%29y%2Fcross%285%29=%281%2B10x%29%2F5
y=%281%2F5%29%2B%2810%2F5%29x
y=%281%2F5%29%2B2x, red%28EQN3%29

Then,
15x-10%28highlight%281%2F5%2B2x%29%29=-1
15x-10%2F5-20x=-1
15x-20x=-1%2B10%2F5=-1%2B2
-5x=1 ---> cross%28-5%29x%2Fcross%28-5%29=1%2F-5
red%28x=-1%2F5%29, subst. in red%28EQN3%29

y=%281%2F5%29%2B2%28highlight%28-1%2F5%29%29
y=%281%2F5%29-2%2F5
red%28y=-1%2F5%29

These 2 lines intersect at point (-1/5,-1.5) or (-0.20,-0.20)

We'll see,
---> red%28RED=EQN1%29; green%28GREEN=EQN2%29

Thank you,
Jojo