The position of the known real number AB on the number axis is shown in the figure: try to simplify: root (a-b) &# 178; - | a + B|

The position of the known real number AB on the number axis is shown in the figure: try to simplify: root (a-b) &# 178; - | a + B|

Key points: remove the absolute value sign, root sign
Yitude a > 0, b|a|, a + B0
so
Radical (a-b) & #178; = |a-b | = a-b
|a+b|=-(a+b)
The original formula = a-b - [- (a + b)] = A-B + A + B = 2A