Question

很着急，明天就要交了，拜托帮帮忙

上图废掉

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Answer 1

-2又1/2÷(-5)×1/5
=-5/2×(-1/5)×1/5
=5/2×1/5×1/5
=1/10

(1又3/4-7/8-7/12)÷(-1又3/4)
=(7/4-7/8-7/12)×(-4/7)
=7/4×(-4/7)+7/8×4/7+7/12×4/7
=-1+1/2+1/3
=-1/6

(-1又1/2)³×3^(-2)+2º
=(-3/2)³×1/3²+1
=-27/8×1/9+1
=-3/8+1
=5/8

π+√3-2/3 ( 精确到0.01)
≈3.142-1.732-0.667
≈0.74

已知x是|-3|的相反数，y是-2的绝对值，求2x²-y²
|-3|=3，3的相反数是-3， x=-3
y=|-2|=2
2x²-y²=2×(-3)²-2²
=2×9-4
=18-4
=14