Answer:
Explanation:
Factor to solve.
12a2 + a – 35 = 0
>Multiply the first and the last, 12 and -35
(12)(-35) = -420
> Find 2 numbers that multiply to -420 but add to middle term, 1
-20 and +21 multiply to -420 but adds to 1
>Replace the middle term with -20 and 21
12a² + a – 35 = 0
12a² + 20a - 21a – 35 = 0
>Group the first 2 and last 2 terms
( 12a² + 20a) (- 21a – 35) = 0
>Take out GCF from each of the groupings
4a ( 3a + 5) -7(3a + 5) = 0
>Take out GCF (3a + 5)
( 4a - 7) ( 3a + 5) = 0
>Set each =0 and solve for a
( 4a - 7) = 0 ( 3a + 5) = 0
a=7/4 a = -5/3