What is the solution to the system of equations: #5x + 2y = -7#, and #-5x + y = 19#?

2 Answers
Mar 8, 2018

#(-3,4)#

Explanation:

We have:

#((5x+2y=-7),(-5x+y=19))#

Adding the two equations, we get:

#3y=12#

#y=4#

Inputting this into one of the equations:

#5x+2(4)=-7#

#5x=+8=-7#

#5x=-15#

#x=-3#

So the solution set is #(-3,4)#

Mar 8, 2018

#color(darkred)(therefore x=-3 and y=4#

Explanation:

#-5x+y=19#

#y=19+5x#

Given that,

#5x+2y=-7#

#5x+2(19+5x)=-7#

#5x+38+10x=-7#

#5x+10x=-7-38#

#15x=-45#

#x=-45/15#

#color(red)(x=-3#

#y=19+5x#

#y=19+5xx-3#

#y=19-15#

#color(magenta)(y=4#

#color(darkred)(therefore x=-3 and y=4#

~Hope this helps! :)