Question

which expression represents the situation "add seven to the product of a number and ten?
A-10(z+7)
B-7+z+10
C-10z+7
D-7z+10z
Which one?

Answer 1

"the product of a number and ten" thats your key. "A number" means we need a varible. In this case - Z. So, 10z. "add seven" +7. "10z+7" - answer C. Does that help a bit?