EX-07 / AP02

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a. $A = (x+2)(2x-3) = 2x^2 - 3x + 4x - 6 = 2x^2 + x - 6$.

b. $B = (x-4)x + (x-3)(x+1)$
$= {x^2} - 4x + x^2 + x -3x - 3 = 2x^2 -6x - 3$.

c. $C = (3x - 2)^2 = (3x)^2 - 2\cdot 3x \cdot 2 + 2^2 = 9x^2 -12x + 4$.

d. $D = (2x+1)^2 - (x-3)^2$
$= (2x)^2 + 2\cdot2x\cdot1 + 1^2 - (x^2 - 2\cdot x \cdot 3 + 3^2)$
$=4x^2 + 4x + 1 -(x^2 -6x + 9)$
$=4x^2 + 4x + 1 -x^2 +6x - 9 =3x^2 + 10x -8.$

e. $E = \left(\dfrac12x+1\right)\left(x+\dfrac25\right)$
$=\dfrac12x \cdot x + \dfrac12x\cdot\dfrac25+1\cdot x + 1\cdot \dfrac25 =\dfrac12x^2+\dfrac15+x+\dfrac25$
$=\dfrac12x^2 + \dfrac65x + \dfrac25$.

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code : 1301