Algebra · real student question

Divide 2x^2 + 2x + 1 by 2x + 3. Give the quotient and the remainder.

Question

Find the quotient and remainder of (2x2+2x+1)÷(2x+3)(2x^2+2x+1)\div(2x+3).

Step-by-step solution

  1. Set up the division. Every power of xx is already present in 2x2+2x+12x^2+2x+1, so no placeholder is needed. The divisor 2x+32x+3 is non-monic, which means fractional quotient coefficients are normal here.

  2. First round. 2x22x=x\dfrac{2x^2}{2x}=x. Multiply back: x(2x+3)=2x2+3xx(2x+3)=2x^2+3x. Subtract: (2x2+2x+1)(2x2+3x)=x+1.(2x^2+2x+1)-(2x^2+3x)=-x+1.

  3. Second round. x2x=12\dfrac{-x}{2x}=-\dfrac12. Multiply back: 12(2x+3)=x32-\tfrac12(2x+3)=-x-\tfrac32. Subtract: (x+1)(x32)=1+32=52.(-x+1)-\left(-x-\frac32\right)=1+\frac32=\frac52.

  4. Stop at the right moment. The leftover 52\tfrac52 has degree 00, below the degree of 2x+32x+3, so the process ends: quotient x12x-\tfrac12, remainder 52\tfrac52.

  5. Verify. (x12)(2x+3)+52=2x2+3xx32+52=2x2+2x+1.\left(x-\frac12\right)(2x+3)+\frac52=2x^2+3x-x-\frac32+\frac52=2x^2+2x+1. Notice the quotient matches the previous problem while the remainder does not — changing the divisor constant only moves the leftover.

Answer

quotient x12,remainder 52\text{quotient }x-\frac{1}{2},\qquad\text{remainder }\frac{5}{2}

Need to solve a different problem like this? Open the solver →