Question

Using substitution method 27x+31y=8531x+27y=89

Answer 1

step 1) add both equations
step 2) subtract both equation
$27x + 31x + 31y + 27y = 85 + 89 \\ 58x + 58y =174 \\ x + y = 3 \: \: \: \: \: eq1 \\ (27 - 31)x + (31 - 27)y = 85 - 89 \\ - 4x + 4y = - 4 \\ - x + y = - 1 \: \: \: \: eq2 \\ add \: both \: eqs \\ 2y = 2 \\ y = 1 \\ x + 1 = 3 \\ x = 2$