√0.81-√0.04
=0.9-0.2
=0.7,
√12又1/4
=√(49/4)
=7/2

√9/4-√49
=3/2-7
=-11/2

√1又9/16-√144+√81
=5/4-12+9
=-7/4

√25X√（-1/5）²-√（-6）³X1/√36
=5×1/5+1
=2.