Solve Rational Expression: (2x+1)²/(x+2) + (x+2)²/(2x+1) = 4.5x

Question

Solve the following equation:

(2x+1)2x+2+(x+2)22x+1=4.5x \frac{(2x+1)^2}{x+2}+\frac{(x+2)^2}{2x+1}=4.5x

Step-by-Step Solution

To solve the equation, let's start by getting rid of the denominators.

To do this, we'll multiply the denominators:

(2x+1)2(2x+1)+(x+2)2(x+2)=4.5x(2x+1)(x+2) (2x+1)^2\cdot(2x+1)+(x+2)^2\cdot(x+2)=4.5x(2x+1)(x+2)

Let's start by opening the parentheses on the left side, mainly using the distributive property:

(4x2+4x+1)(2x+1)+(x2+4x+4)(x+2)=4.5x(2x+1)(x+2) (4x^2+4x+1)\cdot(2x+1)+(x^2+4x+4)\cdot(x+2)=4.5x(2x+1)(x+2)

Let's continue by opening the parentheses on the right side of the equation:

(4x2+4x+1)(2x+1)+(x2+4x+4)(x+2)=4.5x(2x2+5x+2) (4x^2+4x+1)\cdot(2x+1)+(x^2+4x+4)\cdot(x+2)=4.5x(2x^2+5x+2) Let's continue and open the parentheses on the right side of the equation:

(4x2+4x+1)(2x+1)+(x2+4x+4)(x+2)=9x3+22.5x+9x (4x^2+4x+1)\cdot(2x+1)+(x^2+4x+4)\cdot(x+2)=9x^3+22.5x+9x

Now let's go back and simplify the parentheses on the left side of the equation:

8x3+8x2+2x+4x2+4x+1+x3+4x2+4x+2x2+8x+8=9x3+22.5x+9x 8x^3+8x^2+2x+4x^2+4x+1+x^3+4x^2+4x+2x^2+8x+8=9x^3+22.5x+9x

Let's combine like terms:

9x3+18x2+18x+9=9x3+22.5x+9x 9x^3+18x^2+18x+9=9x^3+22.5x+9x

Notice that all terms can be divided by 9, so let's do that:

x3+2x2+2x+1=x3+2.5x+x x^3+2x^2+2x+1=x^3+2.5x+x

Let's move all numbers to one side:

x3x3+2x22.5x2+2xx+9=0 x^3-x^3+2x^2-2.5x^2+2x-x+9=0

And we get:

0.5x2x1=0 0.5x^2-x-1=0

To get rid of the one-half coefficient, let's multiply the entire equation by 2

x22x2=0 x^2-2x-2=0

Now we can use the square root formula, and we get-

2±122 \frac{2±\sqrt{12}}{2}

Let's use the properties of square roots to simplify the square root of 12:

2±232 \frac{2±2\sqrt{3}}{2} Let's divide both numerator and denominator by 2 and we get:

1±3 1±\sqrt{3}

Answer

x=1±3 x=1±\sqrt{3}