SOLUTION: How can I solve the system of equations x^2+y^2=100 3x-y=10

Algebra ->  College  -> Linear Algebra -> SOLUTION: How can I solve the system of equations x^2+y^2=100 3x-y=10      Log On


   

Question 375020: How can I solve the system of equations
x^2+y^2=100
3x-y=10
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x%5E2%2By%5E2=100
2.3x-y=10
Use substitution,
From eq. 2,
y=3x-10
y%5E2=9x%5E2-60x%2B100
Substitute into eq. 1,
x%5E2%2B9x%5E2-60x%2B100=100
10x%5E2-60x=0
10x%28x-6%29=0
Two solutions:
10x=0
highlight%28x=0%29
Then
y=3%280%29-10
highlight%28y=-10%29
.
.
.
x-6=0
highlight_green%28x=6%29
Then
y=3%286%29-10
y=18-10
highlight_green%28y=8%29
.
.
.