Page 112 - Math Course 2 (Book 1)

Polynomial Expressions

Product of a Sum and Real World Example
Difference
GEOMETRY
Example Write an expression that represents the area of a
square that has a side length of 2x + 12 units.
Find (9d + 4)(9d – 4). 2
The formula for the area of a square is A = s .
(a + b)(a – b) = a2 – b 2 A = s Area of a square
2
2
2
(9d + 4)(9d – 4) = (9d) – (4) a = 9d and b = 4
2
A = (2x + 12) s = (2x + 12)
2
Answer 81d – 16 Simplify.
2
2
A = (2x) + 2(2x)(12) + (12) a = 2x and b = 12
2
A = 4x + 48x + 144 Simplify.
The area of the square is
Answer 4x2 + 48x + 144 square units.
Your Turn!

Square of a Sum Real World Example

2
Find (3x + 2) . GEOMETRY
Write an expression that represents the area of a
2
A. 9x + 4 square that has a side length of
2
B. 9x + 6x + 4 (3x – 4) units.
C. 9x + 4
2
2
D. 9x + 12x + 4 A. 9x – 24x + 16 units 2
2
B. 9x + 16 units 2
2
Answer C. 9x – 16 units 2
2
D. 9x – 12x + 16 units 2
Square of a Difference
2
Find (2m – 3) . Answer
2
A. 4m + 9
2
B. 4m – 9
2
C. 4m – 6m + 9
2
D. 4m – 12m + 9

Answer

Product of a Sum and Difference

Find (3y + 2)(3y – 2).

2
A. 9y + 4
2
B. 6y – 4
2
C. 6y + 4
2
D. 9y – 4

Answer

104