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(7.88+6.77+5.66)×(9.31+10.98+10)-(7.88+6.77+5.66+10)×(9.31+10.98)=.

题目详情
(7.88+6.77+5.66)×(9.31+10.98+10)-(7.88+6.77+5.66+10)×(9.31+10.98)=______.
▼优质解答
答案和解析
设9.31+10.98=a,7.88+6.77+5.66=b,则:
(7.88+6.77+5.66)×(9.31+10.98+10)-(7.88+6.77+5.66+10)×(9.31+10.98),
=b×(a+10)-(b+10)×a,
=ab+10b-ab-10a,
=10×(b-a),
=10×[7.88+6.77+5.66-(9.31+10.98)],
=10×[20.31-20.29],
=10×0.02,
=0.2.