Hannahred2 wrote:Here's the problem: square root x-8 (all under square root) + square root x-7 (all under square root) =5. I know you have to subtract square root x-7 from the one side and do it to the side with the 5 too. I know you square both to remove the square root. When you foil, you get a lot of stuff, but here's the important part: do you get -x-7, -x+7, or x-7? Because when I foiled, I got square root x-7 -5 square root x-7. Since there is a neg sign before the 5's, do you distribute it to the whole thing, or just leave it as x-7?!
I used an algebra solver to find out what happens when you foil it. It said just x-7. Is that right? For my final answer, I got x=13.76 or 13 19/25
F.O.I.L. will give the same result as if you use distributive property. Working with the acronym, First, Outer, Inner, Last.
Let me use plain text:
Now square both sides.
YOUR tricky part is what to do with the righthand side.
Current Summary, x-8=-10(x-7)^0.5+x+18
From that, you still want to isolate the square root expression and then square both sides, do other simplifications and solve for x.