一道简便运算,跪求各位大侠!51又1/4×4/5+61又1/5×5/6+71又1/6×6/7=====

Question

一道简便运算,跪求各位大侠!
51又1/4×4/5+61又1/5×5/6+71又1/6×6/7
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Answer 1

51又1/4×4/5+61又1/5×5/6+71又1/6×6/7
=51X4/5+1/4X4/5 + 61X5/6+1/5X5/6 +71X6/7+1/6X6/7
=50X4/5+4/5+1/5 +60X5/6+5/6+1/6 +70X6/7+6/7+1/7
=40+1+50+1+60+1
=153