I need help pls branniest

Find the domain of the following expression: 1/(√x)-2

What is the perimeter of an isosceles triangle with each leg measuring 2x+3 and the base measuring 6x-2?

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.