How do you factor # 3x^2+7x+2#?

Question

1248 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-11T21:00:36

#3x^2+7x+2=(x+2)(3x+1)#

#3x^2+7x+2=(x+2)(3x+1)#

Answer 2 · 2016-07-11T21:36:38

#(3x+1)(x+2)#

Both 3 and 2 are prime numbers, so there are not many options..

We need the factors of 3 and 2 which add together to make 7.
All the signsare positive.

#3 = 3 xx1 and 2 = 2 xx 1#
The only possible combinations are:

#3xx1 + 1xx2 = 3+2 = 5 " wrong combination"#
#3xx2 +1xx1 = 6+1 = 7 " right combination"#

Choose factors and cross multiply to get 7.

#" 3 1" rArr 1xx1 = 1#
#" 1 2" rArr 3xx2 =6# 6+1 = 7

The top row is the one bracket.
The bottom row is the other bracket.
#(3x+1)(x+2)#

Verify that these are correct by multiplying out the brackets.