College Algebra & Trigonometry, 2018a

12 CHAPTER 1. ALGEBRA REVIEW
2(x +3) 2 − 4(3x − 1)(x +2)=2(x +3)(x +3)− 4(3x − 1)(x +2)
=(2x +6)(x +3)− 4(3x 2 +5x − 2)
=2x 2 +12x +18− 12x 2 − 20x +8
= −10x 2 − 8x +26
Most examples in this text will distribute the coefficients as the last step before
combining like terms for a final answer.
Simplify:
3x[5 − (2x +7)]+(3x − 2) 2 − (x − 5)(x +4)
This example has three expressions that should be simplified separately before
combining like terms. In the first expression 3x[5 − (2x +7)], we should simplify
inside the brackets before distributing the 3x.
3x[5 − (2x +7)]+(3x − 2) 2 − (x − 5)(x +4)
=3x[5 − 2x − 7] + (3x − 2) 2 − (x − 5)(x +4)
=3x[−2x − 2] + (3x − 2)(3x − 2) − (x 2 − x − 20)
= −6x 2 − 6x +(9x 2 − 12x +4)− x 2 + x +20
= −6x 2 − 6x +9x 2 − 12x +4− x 2 + x +20
=2x 2 − 17x +24