Question

Which equation is equivalent to StartRoot x squared + 81 EndRoot = x + 10?
x + 9 = x + 10
x + 9 = x2 + 20x + 100
x2 + 81 = x2 + 100
x2 + 81 = x2 + 20x + 100

Answer 1

Square both sides: (√(x^2 + 81))^2 = (x + 10)^2, giving x^2 + 81 = x^2 + 20x + 100. So the correct choice is
x^2 + 81 = x^2 + 20x + 100.