how do you simplify (sqrt18)over(sqrt8)-3? And (4-3sqrt2)squared? I tried but get some unreal answer. thanks in advance.
√18/(√18-3)
recall that (a-b)(a+b) = a^2-b^2. So, multiply by the "conjugate" to get
√18(√18+3) / (√18-3)(√18+3)
= (18+3√18)/(18-9)
= (18+3√18)/9
= (6+√18)/3
= 3+√2
(4-3√2)^2
= 4^2 - 2(4)(3√2) + (3√2)^2
= 16 - 24√2 + 18
= 34 - 24√2