Keep in mind, the phrase “a number” means a certain variable.
“less than” means subtract.
“product” means multiply.
“times” means multiply.
When a variable & a multiplication question is near eachother, a multiply sign is NOT required.
A dot means multiply.
So does “x”
15) (3x3)x4-4
16) 6-b7
17)8/2 . b
18) 3 . b9
Hope this helps you in the future!