Answer:
X=2.5
Step-by-step explanation:
38÷4 = 9.5
9.5 - 7=2.5
Divide each side by four to get rid of that numbr from the elft and subtract seven from both sides to get rid of the seven so your left with x=2.5
Use multiplication:

This question is basically the same as the other question of yours that I answered, so the explanation is very similar:
You can imagine the possibilities as leaves on a tree. Your tree has 2 large branches to represent the two possible sizes. Each of those branch off into 8 smaller branches, each representing a crust flavor. Each one of the smaller branches has 8 leaves to represent a different topping. Each leaf is a combination of a size, a crust flavor, and a topping, so it represents a complete pizza. Your job is to calculate the number of leaves.
Answer: 14/5
Step-by-step explanation:
I will do (a) only.
6rt - 3st + 6ru - 3su
6rt - 3st = 3t(2r - s)
6ru - 3su = 3u(2r - s)
Answer: (3t + 3u)(2r - s)
Do the rest likewise.