$\"\"$

Elimination method:

The system of equations are

$\"\"$ ----------(1)

$\"\"$ ----------(2)

In the above system the coefficients of f - variable are same. $\"\"$

Subtract the equations to eliminate the f - variable and solve the equation.

$\"\"$

The resultant equation is $\"\"$ .

Divide each side by 5.

$\"\"$

The value of $\"\"$ substitute in either equation to find f.

First equation: $\"\"$ .

$\"\"$

Subtract 15 from each side.

$\"\"$

Divide each side by 7.

$\"\"$

The solution is $\"\"$ .