Answer:
Problem 1 : Option B, x = 9
Problem 2: Option A, r = 45
Problem 3: Option D, m = 7
Problem 4: Option B, b/2 - 4 = 9; Total Bill was $26
Problem 5: Option C, 3h + 5 = 11; h = 2
Explanation:
Problem 1
Step 1: Add 3 to both sides
2x - 3 + 3 = 15 + 3
2x = 18
Step 2: Divide both sides by 2
2x / 2 = 18 / 2
x = 9
Answer: Option B, x = 9
Problem 2
Step 1: Add 4 to both sides
r/3 - 4 + 4 = 11 + 4
r/3 = 15
Step 2: Multiply both sides by 3
r/3 * 3 = 15 * 3
r = 45
Answer: Option A, r = 45
Problem 3
Step 1: Subtract 7 from both sides
7 + 3m - 7 = 28 - 7
3m = 21
Step 2: Divide both sides by 3
3m / 3 = 21 / 3
m = 7
Answer: Option D, m = 7
Problem 4
Step 1: Make an expression
b/2 -> You and your friend
-4 -> You owe to your friend
9 -> Total your friend gives you
Equation: b/2 - 4 = 9
Step 2: Add 4 to both sides
b/2 - 4 + 4 = 9 + 4
b/2 = 13
Step 3: Multiply both sides by 2
b/2 * 2 = 13 * 2
b = $26
Answer: Option B, b/2 - 4 = 9; Total Bill was $26
Problem 5
Step 1: Make an expression
3h -> 3 dollars an hour
+5 -> Initial cost
11 -> Total Cost
Equation: 3h + 5 = 11
Step 2: Subtract 5 from both sides
3h + 5 - 5 = 11 - 5
3h = 6
Step 3: Divide both sides by 3
3h / 3 = 6 / 3
h = 2
Answer: Option C, 3h + 5 = 11; h = 2