SOLUTION: solve this equation using the substitution method x+y=20 x-y=4

Algebra.Com
Question 775421: solve this equation using the substitution method
x+y=20
x-y=4

Answer by sofiyac(983)   (Show Source): You can put this solution on YOUR website!
add y to each side of the equal sign of the second equation
a) x=4+y now plug that into the first equation
4+y+y=20
4+2y=20 subtract 4 from each side
2y=16 divide each side by 2
y=8 now plug that into equation marked with a)
x=4+8
x=12
so the solution is (12,8)

RELATED QUESTIONS

Solve this system using the substitution method: y = 3x - 2; y = (1/2)x -... (answered by greenestamps)
how can i solve this equation using substitution method? x+y=12... (answered by Fombitz)
Using the Substitution method, how would you solve x-y=12 and x+y=20? (answered by TimothyLamb)
Can you Please Help Me Solve This equation by using the substitution method? -x+y+0... (answered by jim_thompson5910)
how can i solve this equation using substitution method? x=y+10... (answered by Fombitz)
How would you solve this equation, by either using the substitution method or the... (answered by jim_thompson5910)
solve each systm of equation using the substitution pr elimination method x+y=-4... (answered by solver91311)
Please help me to solve this equation by using substitution method. 5x - 3y = -4 x + y... (answered by Fombitz)
I need to solve this equation by using the Substitution method x + y = 7 2x + 2y =... (answered by Ed Parker)