Step-by-step explanation:
3a²-7a−6
Factor the expression by grouping. First, the expression needs to be rewritten as 3a
2
+pa+qa−6. To find p and q, set up a system to be solved.
p+q=−7
pq=3(−6)=−18
Since pq is negative, p and q have the opposite signs. Since p+q is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product −18.
1,−18
2,−9
3,−6
Calculate the sum for each pair.
1−18=−17
2−9=−7
3−6=−3
The solution is the pair that gives sum −7.
p=−9
q=2
Rewrite 3a
2−7a−6 as (3a
2−9a)+(2a−6).
(3a 2−9a)+(2a−6)
Factor out 3a in the first and 2 in the second group.
3a(a−3)+2(a−3)
Factor out common term a−3 by using distributive property.
(a−3)(3a+2)
