Answer:
Step-by-step explanation:
Whether we divide using long division or using synthetic division, the rule is the same: If, after division, there is no remainder (i. e., the remainder is zero), the divisor binomial is a factor or the associated root is indeed a root/zero/solution.
Divide 5x³+8x²-7x-6 by (x+2) using synthetic division. Use the divisor -2 (which comes from letting x+2 = 0):
--------------------------
-2 / 5 8 -7 -6
-10 4 6
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5 -2 -3 0 Since the remainder here is 0, we know that
-2 is a root of 5x³+8x²-7x-6 and that (x+2) is
a factor of 5x³+8x²-7x-6.
Now check out the possibility that (x+1) is a factor of 5x^3 + 8x^2 - 7x - 6:
Use -1 as the divisor in synthetic division:
--------------------------
-1 / 5 8 -7 -6
-5 -3 10
------------------------------
5 3 -10 4
Since there is a non-zero remainder (4), we can conclude that (x + 1) is NOT a factor of the given polynomial expression.
