Identify a, b, c: Identify a, b, and c in the quadratic expression 3x2+22x+7. Compare 3x2+22x+7 with ax2+bx+c. a=3b0b1
Find product and sum: Find two numbers whose product is a∗c (3∗7=21) and whose sum is b (22).We need to find two numbers that multiply to 21 and add up to 22.The numbers 1 and 21 satisfy these conditions.1∗21=211+21=22
Rewrite middle term: Rewrite the middle term 22x using the two numbers found in Step 2.3x2+22x+7 can be rewritten as 3x2+x+21x+7.
Factor by grouping: Factor by grouping.Group the terms: 3x2+x + 21x+7.Factor out the greatest common factor from each group.From the first group, we can factor out x: x(3x+1).From the second group, we can factor out 7: 7(3x+1).
Factor common binomial: Factor out the common binomial factor.We now have x(3x+1)+7(3x+1).The common binomial factor is (3x+1).The factored form is (3x+1)(x+7).