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What are the solutions to this equation?3 over 2x-5 =x

What are the solutions to this equation?3 over 2x-5 =x-example-1
User Amchew
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1 Answer

16 votes
16 votes

Ok so the first thing you should do is take de therm 2x-5 and pass it to the other side of the equation multiplying. After that you can distribute the product like this:


3=x\cdot(2\cdot x-5)=2x^2-5x

Then you can pass the 3 to the other side so you have a square function equal to 0:


2x^2-5x-3=0

This equation means that you have to look for the roots of a square function. Given a general square function:


ax^2+bx+c

Its roots (also named zeroes) are given by:


x_1,x_2=\frac{-b\pm\sqrt[]{b^2-4\cdot a\cdot c}}{2\cdot a}

In our problem we have a=2, b=-5 and c=-3. Therefore the roots of the square funtion are:


x_1,x_2=\frac{-(-5)\pm\sqrt[]{(-5)^2-4\cdot2\cdot(-3)}}{2\cdot2}=\frac{5\pm\sqrt[]{25+24}}{4}=(5\pm7)/(4)

The symbol between 5 and 7 means that one root is calculate by adding and the other by substracting:


x_1=(5+7)/(4)=3
x_2=(5-7)/(4)=-0.5

So the roots are 3 and -0.5 and are the two possible values for x. Therefore the correct answer is item A.

User Tim Fuqua
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