How do you solve the system of equations 2x-y=712xy=71 and 3y=x3y=x using substitution?

1 Answer
Feb 17, 2017

(142/5 , 71/5)(1425,715)

Explanation:

2x-y=712xy=71 and 3y=x3y=x

you just substitute one equation into the other
since x=3yx=3y you can just insert that into 2x-y=712xy=71

2(3y)-y=712(3y)y=71
6y-6=716y6=71
5y=715y=71
y=71/5y=715

then we plug this y-value into either equation
2x-71/5=712x715=71
2x=284/52x=2845
x=284/10=142/5x=28410=1425

(142/5 , 71/5)(1425,715)