How do you solve the following system: #5x+2y=20 , 3x+4y=-10 #?

1 Answer
Mar 3, 2016

Answer:

The solution for the system of equations is:

#color(blue)(x=50/7#

#color(blue)(y = -55/7#

Explanation:

#5x+2y=20#, multiplying by #2#
#10x+color(blue)(4y)=40#.......equation #(1)#

#3x +color(blue)(4y)=-10#.....equation #(2)#

Solving by elimination.

Subtracting equation #(2)# from #(1)# results in elimination of #color(blue)(4y#

#10x+cancelcolor(blue)(4y)=40#
#-3x -cancelcolor(blue)(4y)=10#

#7x=50#

#color(blue)(x=50/7#

Finding #y# from equation #1#

#5x+2y=20#

#2y=20 -5x#

#2y=20 -5 xx 50/7#

#2y=20 - 250/7#

#2y=140/7 - 250/7#

#2y=- 110/7#

#y=- 110/(7 xx2)#

#color(blue)(y = -55/7#