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

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Answer 1 · 2018-05-15T15:21:55

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

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):}#