Answer is 55 Two ways you can approach this first you can subtract the three from the 10 and get 7. Square that to get 49. Now you know that x-6 has to equal 49 and the only option greater than 49 is 55 Second you can just take the problem step by step. Subtract three from both sides. Sqrt x-6 =7 Square both sides X-6=7^2 x-6=49 Add six to each side X=55