Respuesta :

so you do
distribute
a(b+c)=ab+ac
9(x+5)=9x+9 times 5=9x+45

7(x-3)=7x+7 times -3=7x-21

so now we have
9x+45+7x-21
group like terms
9x+7x+45-21
add
16x+24

simplified is 16x+24