1. You can add 7 units to both sides of the scale so it becomes a balance between x on the left and 21 on the right.
x ___ 21
1A) The only number from the set that will keep the balance is x ∈ {21}
1B) The number on the right (21) will be more than x for x ∈ {0, 1, 7, 14}
1C) The number on the right (21) will be less than x for x ∈ {28, 30}
2A) (x +x +x) +(2 +4) = 102
3x +6 = 102 . . . . . . . . simplified equation
2B) Solving the equation, you have
3x = 102 -6
x = 96/3 = 32
The number that could be a value of x is 32.
13a.) If you're dividing and the base (in this case the base is 10) is the same, subtract the exponents.
13b.) If you're multiplying and the base is the same, then you add the exponents:
13c.) This is similar to 13b:
Remark
The key step is just to subtract 5 from both sides. The pointed of the inequality still points away from the variable and towards the number. As long as that remains true, the correct answer can be found.
Solution
2.7 ≤ b + 5 Subtract 5 from both sides.
2.7 - 5 ≤ b
- 2.3 ≤ b Write with the variable on the left.
b ≥ - 2.3 <<<< answer
