用递等式计算(能简算的请简算)①4.68+14.79+5.32-10.79②2.5×(6.8+6.8+6.8+6.8)③
1个回答

①4.68+14.79+5.32-10.79,

=(4.68+5.32)+(14.79-10.79),

=10+4,

=14;

②2.5×(6.8+6.8+6.8+6.8),

=2.5×(6.8×4),

=2.5×6.8×4,

=(2.5×4)×6.8,

=10×6.8,

=68;

③475+238-147×3,

=475+238-441,

=713-441,

=272;

④49.8+42÷15×4.5,

=49.8+2.8×4.5,

=49.8+12.6,

=62.4;

⑤0.5×[21.2÷(4.5+80%)],

=0.5×[21.2÷5.3],

=0.5×4,

=2;

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