Identify a, b, c: Identify a, b, and c in the quadratic expression 4d2+12d+5 by comparing it with the standard form ax2+bx+c. a=4 b=12 b0
Find Multiplying Numbers: Find two numbers that multiply to a∗c (which is 4∗5=20) and add up to b (which is 12).We need to find two numbers that satisfy these conditions.
Check Factors: After checking possible pairs of factors of 20, we find that 2 and 10 multiply to 20 and add up to 12.So the two numbers we are looking for are 2 and 10.2×10=202+10=12
Rewrite Middle Term: Rewrite the middle term (12d) using the two numbers we found (2 and 10) to split it into two terms.4d2+12d+5 becomes 4d2+2d+10d+5.
Factor by Grouping: Factor by grouping. Group the first two terms and the last two terms.(4d2+2d)+(10d+5)
Factor out Common Factor: Factor out the greatest common factor from each group. 2d(2d+1)+5(2d+1)
Factor out Common Factor: Factor out the greatest common factor from each group.2d(2d+1)+5(2d+1)Since both groups contain the common factor (2d+1), factor this out.The factored form of the expression is (2d+1)(2d+5).
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