Week 5: Student Response To Discussion 1

Collapse SubdiscussionLiwei Loh

Jul 2, 2017Jul 2 at 11:15pm

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err, it did it again...

Factoring

My assigned number is 26. On Page 345-6, I going to solve different types of factoring problems on #52 & #106 and Page 353, I going to address issues of factoring of the #64 as below:

#52. 18z + 45 + z^2

= (z^2 + 3z) + (15z + 45) a =1, c = 45, so ac = 1(45). The factor pairs of 45 are 1, 45 & 3, 15 & 5, 9

3(15)=45 while 3+15= 18 so replace 18z by 3z and 15z

= z(z + 3) + 15(z+3) Factor out z from (z^2 + 3z) and 15 from (15z + 45), I got the comon factor of each group is (z +3)

= (z + 3)(z + 15) here is the completely factored.

#106. ac + xc + aw^2 + xw^2

= a(c +w^2) + cx + xw^2 Four terms means start with grouping, factor out common term a first

= a(c + w^2) + x(c + w^2) Factor out common term x on the next, I notice the comon factor of each group is (c + w^2)

= (c + w^2)(a + x) here is the completely factored

#64. 3x^2-17x+10

= (3x^2 - 2x) + (-15x + 10) a = 3, c = 10, so ac = 3(10). The factor pairs of 30 are 1,30 & 2, 15 & 3, 10.

-2(-15)=30 while -2+(-15)= -17 so replace -17x by -2x and -15x

= x(3x - 2) - 5(3x - 2) Factor out x from 3x^2 - 2x, I got x(3x - 2), and factor out -5 from -15x + 10, it will be -5(3x - 2)

= (3x - 2) (x - 5) I notice the common term of factor is (3x -2), here is the completely factored