$\"\"$

The equations are

$\"\"$ Equation (1)

$\"\"$ Equation (2) \ \

Multiply the equation (1) by 7.

$\"\"$ Equation (3) \ \

$\"\"$

Subtract equation (3) and Equation (1).

$\"\"$

$\"\"$ (Divide each side by 37)

$\"\"$

Substitute -1 for b in equation (1).

$\"\"$

$\"\"$ (Multiply: $\"\"$ )

Addition property of equality: If a = b then a + c = b + c

$\"\"$ (Add 5 to each side)

$\"\"$ (Additive inverse property:-5+5=0)

$\"\"$ (Add:1 + 5 = 6)

$\"\"$

The solution is $\"\"$ .