Q. Solve the quadratic by factoring.5x2−21x−5=3xAnswer: x=
Move Terms to One Side: Move all terms to one side of the equation to set the equation to zero.Subtract 3x from both sides of the equation 5x2−21x−5=3x.5x2−21x−5−3x=3x−3x5x2−24x−5=0
Identify a, b, c: Identify a, b, and c in the quadratic equationax2+bx+c=0. For the equation 5x2−24x−5=0, a=5, b=−24, and b0.
Find Two Numbers: Find two numbers that multiply to a∗c (5∗−5=−25) and add up to b (−24).The numbers that satisfy these conditions are −25 and 1 because:−25∗1=−25 (which is a∗c)−25+1=−24 (which is b)
Split Middle Term: Rewrite the equation by splitting the middle term using the two numbers found in Step 3.5x2−25x+x−5=0
Factor by Grouping: Factor by grouping.Group the first two terms and the last two terms:(5x2−25x)+(x−5)Factor out the greatest common factor from each group:5x(x−5)+1(x−5)
Factor Common Binomial: Factor out the common binomial factor.The common binomial factor is (x−5).5x(x−5)+1(x−5)=(5x+1)(x−5)
Set Factors Equal: Set each factor equal to zero and solve for x.5x+1=0 and x−5=0For 5x+1=0: Subtract 1 from both sides and then divide by 5.5x=−1x=−51For x−5=0: Add 5 to both sides.5x+1=00
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