3 questions-due in 3 hrs
hotgirl84Example 245.
3(2x−4)(x+5) Multiply the binomials,wewill useFOIL
3(2x2+10x−4x−20) Combine like terms
3(2x2+6x−20) Distribute the 3
6x2+18x−60 Our Solution
40) . 3(2x+3)(6x+9)
Example 248.
(3x+7)(3x −7) Recognize sumand difference
9x2−49 Square both, put subtraction between.Our Solution
Example 249.
(2x−6y)(2x+6y) Recognize sumand difference
4x2−36y2 Square both, put subtraction between.Our Solution
It is interesting to note that while we can multiply and get an answer like a2 − b2
(with subtraction), it is impossible to multiply real numbers and end up with a
product such as a2+b2 (with addition).
Another shortcut used to multiply is known as a perfect square. These are easy
to recognize as we will have a binomial with a 2 in the exponent. The following
example illustrates multiplying a perfect square
34) (8n+7)(8n−7)
Example 234.
(2x2−4x+3)+(5x2−6x+1)−(x2−9x+8) Distribute negative through
2x2−4x+3+5x2−6x+1−x2+9x−8 Combine like terms
6x2−x−4 Our Solution
30) (7n+1−8n4)−(3n+7n4+7)