Identify a, b, c: Identify a, b, and c in the trinomial 2x2+15x+25. Compare 2x2+15x+25 with ax2+bx+c. a=2b0b1
Find two numbers: Find two numbers whose product is a∗c (2∗25=50) and whose sum is b (15).We need to find two numbers that multiply to 50 and add up to 15.10∗5=5010+5=15Two numbers: 10,5
Rewrite middle term: Rewrite the middle term 15x using the two numbers found in Step 2.2x2+10x+5x+25 Now we have four terms instead of three.
Factor by grouping: Factor by grouping.Group the first two terms and the last two terms.(2x2+10x)+(5x+25)Factor out the greatest common factor from each group.2x(x+5)+5(x+5)
Factor common binomial: Factor out the common binomial factor.The common binomial factor is (x+5).Factor this out from both groups.(2x+5)(x+5)