⑴(7/12 - 1又1/2 - 1/4)÷(-1/12)÷(-2又1/3)
=(7/12-18/12-3/12)×(-12)×(-3/7)
=(-14/12)×(-12)×(-3/7)
=-6;
⑵31又1/3 × 41又1/2 -11又1/3 × 41又1/2 × 2 - 9.5 × 11又1/3
=94/3×83/2-34/3×83/2×2-19/2×34/3
=94/3×83/2-34/3×(83/2×2+19/2)
=(94×83-34×185)/6
=252.
⑴(7/12 - 1又1/2 - 1/4)÷(-1/12)÷(-2又1/3)
=(7/12-18/12-3/12)×(-12)×(-3/7)
=(-14/12)×(-12)×(-3/7)
=-6;
⑵31又1/3 × 41又1/2 -11又1/3 × 41又1/2 × 2 - 9.5 × 11又1/3
=94/3×83/2-34/3×83/2×2-19/2×34/3
=94/3×83/2-34/3×(83/2×2+19/2)
=(94×83-34×185)/6
=252.