Q. Solve for all values of x by factoring.x2+2x−15=0Answer: x=
Identify Equation: Identify the quadratic equation to be factored.We have the quadratic equation x2+2x−15=0. We need to find two numbers that multiply to give −15 (the constant term) and add up to 2 (the coefficient of the x term).
Find Numbers: Find two numbers that multiply to −15 and add up to 2. The numbers 5 and −3 satisfy these conditions because 5×(−3)=−15 and 5+(−3)=2.
Rewrite Equation: Rewrite the quadratic equation using the two numbers found.The equation x2+2x−15=0 can be rewritten as x2+5x−3x−15=0 by splitting the middle term using the numbers 5 and −3.
Factor by Grouping: Factor by grouping.Group the terms to factor by common terms: (x2+5x)−(3x+15)=0.Factor out an x from the first group and a −3 from the second group: x(x+5)−3(x+5)=0.
Factor Common Factor: Factor out the common binomial factor.Since both groups contain the factor (x+5), factor it out: (x−3)(x+5)=0.
Solve for x: Solve for x by setting each factor equal to zero.Set the first factor equal to zero: x−3=0, which gives x=3.Set the second factor equal to zero: x+5=0, which gives x=−5.
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