Factor x^2-x-20

Problem

x2−x−20

Solution

1. Identify the coefficients of the quadratic expression in the form a*x2+b*x+c where a=1 b=−1 and c=−20

2. Find two numbers that multiply to c (which is −20 and add to b (which is −1.

3. Determine the factors by testing pairs of numbers that multiply to −20 4 and −5 satisfy the condition because 4×(−5)=−20 and 4 + (-5) = -1$.

4. Write the expression in factored form (x+p)*(x+q) using the numbers found in the previous step.

Final Answer

x2−x−20=(x−5)*(x+4)

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