There is actually 2 ways to solve this, I will show you both.
The first is obvious, solve for x in the first one, and plug it into the 2nd one and get the answer
4x + 7 = 12
4x = 5
x =
8() + 3
2 * 5 + 3
10 + 3
13
The 2nd option is to manipulate the 4x + 7 to be 8x + 3
4x + 7 = 12
start by moving the 7 over
4x = 5
multiply both sides by 2
8x = 10
and add 3 to both sides
8x + 3 = 13
Answer:
substitute that value for x in the polynomial and see if it evaluates to zero
Step-by-step explanation:
A "zero" of a polynomial is a value of the polynomial's variable that make the expression become zero when it is evaluated. As an almost trivial example, consider the polynomial x-3. The value x = 3 is a zero because substituting that value for x makes the expression evaluate as zero.
3 -3 = 0
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Evaluating polynomials can be done different ways. Straight substitution for the variable is one way. Using synthetic division by x-a (where "a" is the value of interest) is another way. This latter method is completely equivalent to rewriting the polynomial to Horner form for evaluation.
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In the attachment, Horner Form is shown at the bottom.
