√32-3√二分之一+√八分之一
=4√2-3/2*√2+1/4*√2
=(4-6/4+1/4)*√2
=(2+3/4)√2
=11√2/4
(√5-√20)除以√125
=(√5-2√5)÷5√5
=-1/5
3.(7+√7)²-(7-√7)²
=2*2*7√7
=28√7
√32-3√二分之一+√八分之一
=4√2-3/2*√2+1/4*√2
=(4-6/4+1/4)*√2
=(2+3/4)√2
=11√2/4
(√5-√20)除以√125
=(√5-2√5)÷5√5
=-1/5
3.(7+√7)²-(7-√7)²
=2*2*7√7
=28√7