Multiply binomials and polynomials, and use them for perimeter and area

Answer Key - Grade 9 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Kira draws the rectangle for (x + 3)(x + 5) and cuts it into four parts, one for each pair of terms. Type x² as x^2. What is the product in fewest terms?

   x^2 + 8x + 15
2. 2.

   Luz draws the rectangle for (x + 4)(x + 6) and cuts it into four parts, one for each pair of terms. Type x² as x^2. What is the product in fewest terms?

   x^2 + 10x + 24
3. 3.

   Noah draws the rectangle for (x + 1)(x + 8) and cuts it into four parts, one for each pair of terms. Type x² as x^2. What is the product in fewest terms?

   x^2 + 9x + 8
4. 4.

   Pia multiplies (x + 7)(x − 2) and gets x² + ?x − 14. What number goes where the ? is?

   5
5. 5.

   Tala multiplies (x + 10)(x − 4) and gets x² + ?x − 40. What number goes where the ? is?

   6
6. 6.

   Zee multiplies (x − 9)(x + 2) and gets x² + ?x − 18. What number goes where the ? is?

   -7
7. 7.

   Ari's rug is (x + 8) by (x + 3) feet (x > 0), so its area is (x + 8)(x + 3). Type x² as x^2. What is the area in fewest terms?

   x^2 + 11x + 24
8. 8.

   Luz's photo frame is (3x + 2) cm by (x + 6) cm, with x at least 1. Its perimeter is 2(3x + 2) + 2(x + 6). What is the perimeter in fewest terms?

   8x + 16
9. 9.

   Milo's photo frame is (4x + 1) cm by (x + 2) cm, with x at least 1. Its perimeter is 2(4x + 1) + 2(x + 2). What is the perimeter in fewest terms?

   10x + 6
10. 10.

    Noah's photo frame is (x + 7) cm by (2x + 3) cm, with x at least 1. Its perimeter is 2(x + 7) + 2(2x + 3). What is the perimeter in fewest terms?

    6x + 20