Week 5: Student Response To Discussion 1
Sarah WoodsWednesdayJul 5 at 4:38pm
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My first problem is number 80 : w2+30w+81
I will be using the ac method which is ax2+bx+c
a = 1
b = 30
c = 81
ac = 1(81) = 81
The factors for 81 are; 1 and 81, 3 and 27, 9 and 9. Out of all the pairs the only one that also equals 30 when added together is 3 and 27.
w2+27w+3w+81 replace 30w with 3w and 27w
w(w+27)+3(w+27) grouping the common factors
(w+27)(w+3) factor out the greatest common factor GCF
Check with FOIL
(w+27)(w+3) = w2+27w+3w+81 combine like terms
= w2+30w+81
My second problem is number 82; 9w-w3
w(9-w2) factor out common factors
w(32-w2) rewrite expression; by changing 9 into 32 we are getting a perfect square number
w(3-w)(3+w)
My last problem is number 90; 18x2-6x+6
I will use the ac method one more time; ax2+bx+c
a = 18
b = -6
c = 6
ac = 18(6) = 108
There are many factors of 108 but a few are 1 and 108, 54 and 2, 36 and 3, 27 and 4
Although neither of these numbers are prime factors, this equation will not factor.
