Question

solve 3 question please fastly i need help

Answer 1

Rationlised the denominator 
= 6-4√2/6+4√2 *6-4√2/6-4√2
= (6 - 4√2)^2 / (6 - 4√2)(6 + 4√2)
= (6)^2 - 2*6*4√2 +(4√2)^2 / (6)^2 - (4√2)^2
= 36 - 48√2 + 16*2 / 36 - 16*2
= 36 - 48√2 + 32 / 36 - 32
= 68 - 48√2 / 4
= 4(17 - 12√2) / 4
= 1(17- 12√2) / 1
⇒ 17-12√2 = a + b√2
a = 17
b = -12