SOLUTION: Solve the system by substitution. x + y = -7 x - y = 13

Algebra.Com
Question 43849: Solve the system by substitution.
x + y = -7
x - y = 13

Found 2 solutions by adamchapman, fractalier:
Answer by adamchapman(301)   (Show Source): You can put this solution on YOUR website!
x+y=-7 ..1
x-y=13 ..2
rearrange equation(..2) to give:
y=x-13 ..3
now substitute equation (..3) into equation (..1) for y:
x+(x-13)=-7
2x-13=-7
2x=6
x=3 ..4
now substitute equation (..4) into equation (..3) for y:
y=3-13
y=-10
Therefore x=3 and y=-10
I hope this helps. If you have any other problems, please dont hesitate to contact me at adam.chapman@student.manchester.ac.uk

Answer by fractalier(6550)   (Show Source): You can put this solution on YOUR website!
From
x + y = -7
x - y = 13
let us solve the first one for x and substitute it into the second...thus we have
x = -y - 7 and
(-y - 7) - y = 13
-y - 7 - y = 13
-2y = 20
y = -10 and then
x = 3

RELATED QUESTIONS

Solve the system by substitution. x + y = -7 x - y = 13 (answered by fractalier)
Solve the system by substitution {{{y=x^2-4}}}... (answered by jim_thompson5910)
Solve system by elimination y-7=x... (answered by solver91311)
solve the system by substitution x^2+y^2=97... (answered by Fombitz)
Solve the system by the substitution method. X+2y=-2... (answered by MathLover1,greenestamps,math_tutor2020)
Solve the system by substitution. x+y=12... (answered by funmath)
Solve the system by substitution. x + y = 12 y =... (answered by jai_kos)
Solve the system by substitution. x + y = 12 (answered by tutorcecilia)
Solve the system by substitution. x + y = 12 (answered by asha)