Answer:
(x +5)(x -2)
Step-by-step explanation:
You are looking for factors of -10 that have a sum of +3.
-10 = -1×10 = -2×5 = -5×2 = -10×1
The sums of these factor pairs are 9, 3, -3, -9, and the pair that is of interest is -2×5.
Those factors are used directly in the binomial factors of the expression:
(x -2)(x +5)
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Obviously, factoring is greatly aided by a mastery of multiplication tables. You can also use a graphing calculator or any of several different algebraic methods to find the roots of the expression (values of x that make it zero). Each root will be the opposite of the constant in the corresponding binomial factor.
In the attached, you can see the roots of this expression are -5 and +2. Compare those to the numbers in the factorization above.
