Answer:is
=x(x-4)-45
Step-by-step explanation:q= (x+5) (x-9)
in the mathematical rules when the variables are in the brackets it means we have to remove the brackets by,multiplying the first variable to the second variable in another bracket, and then so on.
=x^2-9x+5x-45
=x^2-4x-45
by simplifying completely it will become,
=x(x-4) -45
that's the answer.