I dont understand 6 grade math

For [tex]f(x) = 4x+1[/tex] and [tex]g(x) = x^{2} -5[/tex] find [tex](f[/tex] ° [tex]g)[/tex][tex](4)[/tex]

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.

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.