9.1 # 6 square root Help please

Question

x-1=√7-x

 

Question is why do you drop one of the answers. As mentioned before, anytime we raise both sides of an equation to an even power, we must check the answer in the original equation.

 I was told the answer I provided was incorrect

So, please show your check and include it in the original solution for full credit

 

Answer 1

So, are you sure you got the right answers?

 

If the entire right side is under the radical, then an x-value that caused what's under the radical to be negative (7 - 8 for example) would have to be dropped. Neither answer I get, however, makes that happen.

 

If we were looking for measurements, the negative answer would be tossed because we measure positively.

 

If we had a fraction, the denominator couldn't equal 0.

 

I see none of those. I got -2 and 3 as answers, again assuming the entire right side is under the radical.