7 x 18 = 7 x (10 + _ ) =(7 x 10 ) + (7 x _ )

= 70 + _

= _ square units

( " _ " means it needs to be answered )
( BTW this is 3rd-grade math )​

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.