Core Connections Integrated II, 2015
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Core Connections Integrated II, 2015 View details
1. Section 3.1
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Exercise 56 Page 172

Practice makes perfect
a To simplify the expression, we have to expand the parentheses. To do this, all terms in the first set of parentheses has to be multiplied by all terms in the second set of parentheses.

(3 x + 2) (4 x - 5)
3 x* 4x -3x* 5+2* 4x - 2* 5
12 x^2 - 15 x + 8 x - 10
12 x^2 - 7x - 10

b Here, we will use the rules for expanding a squared binomial to simplify the expression.

(4 x - 1)^2
(4x)^2-2 * 4x * 1+1^2
4^2x^2-2 * 4x * 1+1^2
16x^2-2 * 4x * 1+1
16x^2-8x+1

c To solve the equation, we first have to simplify the two sides as far as possible. After that, we can isolate x on one of the equation's sides by performing inverse operations.

2 x (x + 3 ) = (x + 1) (2 x - 5)
â–¼
Solve for x
2x* x + 2x * 3 = (x + 1) (2 x - 5)
2x* x + 2x * 3 = x* 2x-x* 5+1* 2x-1* 5
2x^2 + 6x = 2x^2-5x+2x-5
2x^2 + 6x = 2x^2-3x-5
6x = - 3x-5
9x =- 5
x =- 5/9

d Again, to solve the equation, we have to simplify both sides and then solve for x

3^2+(x+1)^2=(x+2)^2
â–¼
Solve for x
3^2+x^2+2* x* 1+1^2=x^2+2* x* 2+2^2
9+x^2+2* x* 1+1=x^2+2* x* 2+4
9+x^2+2x+1=x^2+4x+4
9+2x+1=4x+4
10+2x=4x+4
6+2x=4x
6=2x
3=x
x=3