5/8÷7/20*4*7/10 5/7*34*7*2/17 88*16/87 (1/4+1/5)*4*5

问题描述:

5/8÷7/20*4*7/10 5/7*34*7*2/17 88*16/87 (1/4+1/5)*4*5

5/8÷7/20*4*7/10
=5/8×20/7×4×7/10
=5
5/7*34*7*2/17
=5/7×7×34×2/17
=5×4
=20
88*16/87
=(87+1)×16/87
=87×16/87+1×16/87
=16+16/87
=16又16/87
(1/4+1/5)*4*5
=1/4×4×5+1/5×4×5
=5+4
=9