,

Subtract from both sides of the equation.

Divide each term by and simplify.

Divide each term in by .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Simplify each term.

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Move the negative in front of the fraction.

Replace all occurrences of in with .

Simplify .

Simplify each term.

Apply the distributive property.

Multiply .

Combine and .

Multiply by .

Multiply .

Multiply by .

Combine and .

Move the negative in front of the fraction.

To write as a fraction with a common denominator, multiply by .

Combine and .

Combine the numerators over the common denominator.

Combine the numerators over the common denominator.

Multiply by .

Add and .

Factor out of .

Factor out of .

Factor out of .

Multiply both sides of the equation by .

Simplify both sides of the equation.

Simplify .

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Cancel the common factor of .

Cancel the common factor.

Rewrite the expression.

Simplify .

Cancel the common factor of .

Factor out of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Move all terms not containing to the right side of the equation.

Subtract from both sides of the equation.

Subtract from .

Replace all occurrences of in with .

Simplify .

Combine the numerators over the common denominator.

Simplify the expression.

Subtract from .

Divide by .

List all of the solutions.

Solve by Substitution 9a+3b=30 , 8a+4b=28