SOLUTION: please help me solve this promblem use the substitution method to solve the linear system here is the promblem x-5y=-10 y=-2x-9 please help

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Question 120687: please help me solve this promblem
use the substitution method to solve the linear system
here is the promblem
x-5y=-10
y=-2x-9
please help
Found 2 solutions by jim_thompson5910, B-Rod33:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
x-5y=-10
y=-2x-9



x-5%28-2x-9%29=-10 Plug in y=-2x-9 into the first equation. In other words, replace each y with -2x-9. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


x%2B10x%2B45=-10 Distribute


11x%2B45=-10 Combine like terms on the left side


11x=-10-45Subtract 45 from both sides


11x=-55 Combine like terms on the right side


x=%28-55%29%2F%2811%29 Divide both sides by 11 to isolate x



x=-5 Divide




Now that we know that x=-5, we can plug this into y=-2x-9 to find y



y=-2%28-5%29-9 Substitute -5 for each x


y=1 Simplify


So our answer is x=-5 and y=1 which also looks like



Notice if we graph the two equations, we can see that their intersection is at . So this verifies our answer.


+graph%28+500%2C+500%2C+-7%2C+7%2C+-7%2C+7%2C+%28-10-x%29%2F-5%2C+-2x-9%29+ Graph of x-5y=-10 (red) and y=-2x-9 (green)

Answer by B-Rod33(7) About Me  (Show Source):
You can put this solution on YOUR website!
x-5y=-10
y=-2x-9
x-5(-2x-9)=-10
x+10x+45=-10
11x=-55
x=-5
y=-2(-5)-9
y=10-9
y=1
x=-5 y=1