How do you solve the system of equations #5x + 5y = 40# and #15x + 8y = 71#?

1 Answer
May 15, 2018

The solution is #{(x=1),(y=7):}#

Explanation:

The equations are

#{(15x+8y=71),(5x+5y=40):}#

Dividing equation #(2)# by #(5)#

#<=>#, #{(15x+8y=71),(x+y=8):}#

#<=>#, #{(15x+8y=71),(y=8-x):}#

Substituting #y# in equation #(1)#

#<=>#, #{(15x+8(8-x)=15x+64-8x=71),(y=8-x):}#

#<=>#, #{(7x=7),(y=8-x):}#

#<=>#, #{(x=1),(y=7):}#