In this problem, we're going to have sqrt -5 X plus 149 -, sqrt X + 80 equaling -3. So we need to get one of the square roots on one side all by itself and everything else on the other side. So I'm going to add that sqrt X + 80 to the other side. Now we're going to square each side. So if I square the left side, the square and the square root are going to cancel. But if we square the right side, we're going to have to foil because there were two terms. So we're going to get negative five X + 149 on the left side. On the right side we're going to get X + 80 minus when we do the outside term and the inside term they're going to be the same. So we're going to get 2 * 3 square roots of X + 80, and then the -3 * -3 is +9. If you're struggling with that, I would recommend writing it out as sqrt X + 80 - 3 times sqrt X + 80 - 3. Then when you do that, hopefully you can maybe see it a little better. The square root times the square root would cancel. When we do the outside terms, we get -3 square roots of X + 80. When we do the inside terms, we get -3 square roots of X + 80. And then the -3 * -3 would give us the +9. So now we're going to combine our like terms, negative five X + 149 = X + 89, the 80 and the nine at the end -6 square roots of X + 80. I'm going to take everything that doesn't have a square root to the other side. So negative six X + 60 equaling -6 square roots of X + 80. So I subtracted X from each side, and I subtracted the 89 from each side. Now I like to have my number small if possible, so I'm actually going to divide everything through by a -6. So I'd get X -, 10 equaling sqrt X + 80. Now I have the square root on one side by itself. To get rid of the square root, I've got to square it. But if I square one side, we're going to have to square the other. So we're going to get X ^2 minus twenty X + 100 equaling X + 80. We're going to take all of the XS to one side, so we're going to have X ^2. Actually, we're going to take everything to one side -20 One X + 20 = 0. We're going to factor that into X - 1 * X - 20. So we're going to see that X equal 1 or 20. Now we absolutely must check these because we squared each side. We absolutely have to check to see if they still work. So sqrt -5 * 1 + 149 minus sqrt 1 + 80. We want to know does that equal -3? So square root -5 + 149 would be 144 -, 80 + 1 would be 81. Sqrt 144 is 12 sqrt 81 is 9. This one does not check, so we know that one isn't a solution. Now if we check our twenty negative 5 * 20 + 149 -, sqrt 20 + 80 does that equal -3? So we'd get -100 + 149. So sqrt 49, which we know is 7 - sqrt 100. Sqrt 100 is 10 does 7 - 10 equal -3 and that one does work. So our answer is going to be X equal 20.