He didn’t multiply the equation by 1/2 in the second part so it threw his whole answer off. Hope this helps
3x2+4(-1)-2(5)2 +4(5)+5=
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6+-4-10+25
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31-14=17
(-9x²-2x) - (-9x²-3x) = (-9x²-2x) +(9x²+3x) = -9x²-2x+9x²+3x = (-9x²+9x²)+(-2x+3x) = x
First, you know that B is the mid point, meaning AB is equal to BC. Therefore, you can set up the equation: x+5=2x-11. Then, you solve for x. Once you are done solving, you should get 16. Hope this helps!
