verbal expressions into equations

Question

for example: 5 increased by twice a number (n is "the number") is 13

another example: 12 is equal to four times the difference of a number and 8

plz help have a test tomorrow and trying to study

thanx

Answer 1

5 + 2n = 13

2n = 8 <--- subtracts 5 from both sides

n = 4 <--- divides both sides by 2

12 = 4(n-8)

12 = 4n - 32 <-- distributes the 4

44 = 4n <--- adds 32 to both sides

n = 11 <--- divides both sides by 4