SAT Math Question of the Day

Math Category: Applied Arithmetic:

Q: (x3y)2(x3y4) =

  1. x5 y5
  2. x6 y5
  3. x6 y6
  4. x8 y6
  5. x9 y6

UNANSWERED.

The correct answer is E.

A: x9 y6 is the right answer.

(x3y)2(x3y4) = x6y2x3y4
= x6 x3 y2 y4
= x(6+3) y(2+4)
= x9 y6

Or expand, if you forget the exponent rules.
(x3y)2(x3y4) = (xxxy)2 (xxx yyyy)
= (xxxy)(xxxy)(xxx yyyy)
= xxx xxx xxx y y yyyy
Then count up the number of x's and y's
= x9 y6