She used the GCF to factor the expression 21x + 56xy as 7(3x + 8xy). Is she correct

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Simplify each expression. use positive exponents. show work . (x –2 y –4 x 3 ) –2

Andy has $310 in his account. each week, w, he withdraws $30 for his expenses. which expression could be used if he wanted to find out how much money he had left after 8 weeks?