Câu 1:
1 .M=2$\sqrt[]{9}$ - 3 $\sqrt[]{64}$
= 6 - 24 = -18
N = $\sqrt[]{(3-√2)²}$ - (5-√2) = 3-√2 - 5 + √2 = -2
2.
P= (1 - $\frac{2}{√x+1}$ ).$\frac{x-1}{√x-1}$
= ($\frac{√x +1 -2}{√x+1}$ ).$\frac{(√x+1)(√x-1)}{√x-1}$
= $\frac{(√x-1)(√x+1)(√x-1)}{(√x+1)(√x-1)}$
= √x-1