Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
Cumulative Standards Review

Exercise 9 Page 493

To divide the given polynomials use synthetic division.

B

Practice makes perfect
To divide the given polynomials using synthetic division, all the terms of the dividend must be present. x^3+2x^2-x+6 Since there are no "missing" terms, we do not need to rewrite the polynomial. Remember that the general form of the synthetic division divisor must be x-a. Therefore, we need to rewrite ours a little bit. x+3 ⇔ x-(-3) Now we are ready to divide!
rl IR-0.15cm r -3 & |rr 1 &2 &-1 &6

Bring down the first coefficient

rl IR-0.15cm r -3 & |rr 1 &2 &-1 &6 &&& & c 1 & & &

Multiply the coefficient by the divisor

rl IR-0.15cm r -3 & |rr 1 &2 &-1 &6 &- 3&& & c 1 & & &

Add down

rl IR-0.15cm r - 3 & |rr 1 &2 &-1 &6 &- 3&& & c 1 & - 1& &
â–Ľ
Repeat the process for all of the coefficients

Multiply the coefficient by the divisor

rl IR-0.15cm r - 3 & |rr 1 &2 &-1 &6 &- 3&3 & & c 1 & - 1& &

Add down

rl IR-0.15cm r - 3 & |rr 1 &2 &-1 &6 &- 3&3 & & c 1 & - 1& 2&

Multiply the coefficient by the divisor

rl IR-0.15cm r - 3 & |rr 1 &2 &-1 &6 &- 3&3 &- 6 & c 1 & - 1& 2 &

Add down

rl IR-0.15cm r - 3 & |rr 1 &2 &-1 &6 &- 3&3 &- 6 & c 1 & - 1& 2& 0
The quotient is a polynomial of degree 2, with the above coefficients. The remainder is 0. Quotient & Remainder x^2-x+2 & 0 This corresponds to answer B.

Checking Our Answer

Checking the answer
We can check our answer by multiplying the quotient by the divisor, and then adding the remainder. If the answer equals the dividend, it means our answer is correct. Let's do it!
(x^2-x+2 ) (x+3) ? = x^3+2x^2-x+6
x^2(x+3)-x(x+3)+2(x+3) ? = x^3+2x^2-x+6
â–Ľ
Simplify left-hand side
x^3+3x^2-x(x+3)+2(x+3) ? = x^3+2x^2-x+6
x^3+3x^2-x^2-3x+2(x+3) ? = x^3+2x^2-x+6
x^3+3x^2-x^2-3x+2x+6 ? = x^3+2x^2-x+6
x^3+2x^2-x+6=x^3+2x^2-x+6 âś“