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If 3x-1=11,what is the value of x^2+x

User Labotsirc
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1 Answer

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We can set the 2nd equation to y that way we have something to solve for

\left \{ {{3x-1=11} \atop {x^2+x=y}} \right.
First we solve our first equation by moving the one to the other side

3x=12
Then we divide by 3 on each side

x=4
So now we can plug 4 into the x's of the 2nd equation

4^2+4=y\\ 16+4=y\\ 20=y
User Dinesh Maurya
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