6 One factor of 2a2 53 is A 3 Ba 1 C z1 D 2r 1 E 2r 3 Soluti
6. One factor of 2a2 53 is (A) -3 (B)a 1 (C) z+1 (D) 2r +1 (E) 2r +3
Solution
2x^2 - 5x + 3
This is a quadratic that can clearly be factored...
So, lets do it...
2x^2 - 5x + 3
Standard quad is ax^ 2+ bx + c
So, by comparing, we get :
a = 2 , b = -5 and c = 3
And rules for factoring a QUADRATIC is :
Sum of two numbers = b
Product of two numbers = ac
So, here we have :
Sum = -5
Product = 2*3 = 6
Now, which two numbers add up to -5 and also multiply to yield 6?
Oh yeah, tis -2 and -3
So, we now have :
2x^2 - 5x + 3 as
2x^2 - 2x - 3x + 3
Now, pair first two terms and last two terms and then factor :
2x(x - 1) - 3(x - 1)
Now, take that x - 1 out in common to get :
(2x - 3)(x - 1)
as the final factored form
So, one of the factors was :
x - 1
Option B is the answer
