Can 12/21 and 15/24 form a proportion?

Use the elimination method to solve the system of equations -x+5y=-4 and 4x+3y=16

Which of the binomials below is a factor of this trinominal? x^2-13+30

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.