PICKING NUMBERS
Sometimes a math problem can seem more difficult than it actually is because it’s general or abstract. You can make a question like
this more concrete—and easier—by substituting numbers for the variables in the question. If you find that you often have difficulty
with algebra problems, you may find that picking numbers helps make the math easier.
EXAMPLEThe algebra in this question is pretty straightforward. According to the distributive property, 3 a(2b + 2) = (3a)(2b) + (3a)(2) = 6ab
- 6 or choice (E). Most test takers will probably do the algebra to solve the question.
However, if you have trouble with algebra—or simply find it takes you a long time—you can approach this problem another way.
Pick simple numbers for a and b and plug them into the equation. If a = 2 and b = 3, then 3 a(2b + 2) = (3)(2)[2(3) + 2] = 6(6 + 2) =
48. Now you know that if a = 2 and b = 3, the equation equals 48.
PICK EASY NUMBERS!
Pick small numbers that are easy to use. This method is supposed to make the problem easier.Once you know this, simply plug 2 in for a and 3 in for b in each of the answer choices. The one that adds up to 48 is the correct
answer.
Choice (E) is the answer that gives you 48 when you plug 2 in for a and 3 for b. Therefore, it must be the correct answer.
55. 3 a(2b + 2) =A. 2 b + 3a
B. 5 ab + 2b
C. 5 ab + 2a +1
D. 6 ab + 2a
E. 6 ab + 6aA. 2 b + 3a = 2(3) + 3(2) = 12
B. 5 ab + 2b = 5(2)(3) + 2(3) = 36
C. 5 ab + 2a + 1 = 5(2)(3) + 2(2) + 1 = 35
D. 6 ab + 2a = 6(2)(3) + 2(2) = 40
E. 6 ab + 6a = 6(2)(3) + 6(2) = 48