(1)-√3×2/√3+2√2(√2-3)
=-2+4-6√2
=2-6√2
(2)√(-2/5)^2-3√-8+√1-(-4/5)^2
=2/5+2+3/5
=1+2
=3
后两题求出x的值
(3)(x+1)^2=121/49
x+1=11/7或x+1=-11/7
x=4/7或x=-18/7
(4)1/2(2x-1)^3=-4
(2x-1)³=-8
2x-1=-2
2x=-1
x=-1/2能在帮我算一题吗？是已知|a+2|+|b+3|=0,求√a^2-7b的算术平方根，拜托了，谢谢你|a+2|+|b+3|=0,a+2=0b+3=0a=-2b=-3√a^2-7b=√(4+21)=5所以√（a²-7b）的算术平方根=√5