The Princeton Review - Princeton Review PSAT 8_9 Prep-Random House Children's Books (2021)

to 110 seeds per container, so eliminate (B). The value was too large,
so try (C) next. Divided among 3 containers, there would be 225 ÷ 3
= 75 seeds per container. Since this is within the range of seeds per
container, you can stop here. The correct answer is (C), and you
didn’t even need to set up an inequality to solve!
Neat, huh? Let’s try one more.
9. Given the equations –a + 4b = 8 and 2a + 4b = 20, what is the
value of a if (a, b) is the solution to the system of equations?
A) –12
B) 3
C) 4
D) 12
Here’s How to Crack It
The question asks for the value of a in the system of equations. We
already looked at how to solve systems, but let’s try this one using
PITA. Label the answers as a, and start in the middle with (C), 4.
Plug this value of a into both equations and solve for b.
Both equations yield the same value for b, so we’ve found the correct
value of a. Always be on the look-out for opportunities to plug in or
plug in the answers as you do your PSAT 8/9 practice. Once you get
good at it, you can decide on any test question which way is faster—
solving or Plugging In.