Multiply the values of a and c together;
9*30= 270 <— find prime factors of this
270= 3*3*3*5*2
Now find a way to add these factors in different ways to give 33 (b value)
We can try (3*3*2)+(3*5)=?
18+15=33
Now that you know the numbers, break down the b value.
9x^2+18x+15x+30
9x(x+2)+15(x+2) <— make sure the brackets are the same
(9x+15)(x+2) <— check if this expands to the initial answer
Hope I helped :)
Tv
Kid that
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GfbLmkfh. !. Fhng fnh fny nt
I guess your are selecting them without replacement, if so:
a) P(picking one defective) = 3/12
P(picking a 2nd defective) = 2/11
P(picking a 3rd defective) = 1/10
P(1 and 2 and 3 defective) = 3/12 x 2/11 x 1/10 = 1/220 = 0.0045
b) None defective: P( Non Defective) = 9/12 (follow Same logic):
9/12 x 8/11 x 7/10 = 21/55 = 0.38
Second method using combination:
a) ³C₃ / ¹²C₃ = 1/220 0.0045
B) ⁹C3 / ¹²C³ = 21/55 = 0.38
5/20 or 1/4
Hope this helps
