① 一个数,减去3.5与4的积,差是20的1/2,求这个数是多少?【列方程解答】② 2的倒数与2.5的和除与1/2的商,减去0.5除与1/4的商,差是多少?③ 简便运算 1/5÷12+4/5×1/13③ 简便运算 1/5÷13+4/5×1/13
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![① 一个数,减去3.5与4的积,差是20的1/2,求这个数是多少?【列方程解答】② 2的倒数与2.5的和除与1/2的商,减去0.5除与1/4的商,差是多少?③ 简便运算 1/5÷12+4/5×1/13③ 简便运算 1/5÷13+4/5×1/13](/uploads/image/z/387314-26-4.jpg?t=%E2%91%A0+%E4%B8%80%E4%B8%AA%E6%95%B0%2C%E5%87%8F%E5%8E%BB3.5%E4%B8%8E4%E7%9A%84%E7%A7%AF%2C%E5%B7%AE%E6%98%AF20%E7%9A%841%2F2%2C%E6%B1%82%E8%BF%99%E4%B8%AA%E6%95%B0%E6%98%AF%E5%A4%9A%E5%B0%91%3F%E3%80%90%E5%88%97%E6%96%B9%E7%A8%8B%E8%A7%A3%E7%AD%94%E3%80%91%E2%91%A1+2%E7%9A%84%E5%80%92%E6%95%B0%E4%B8%8E2.5%E7%9A%84%E5%92%8C%E9%99%A4%E4%B8%8E1%2F2%E7%9A%84%E5%95%86%2C%E5%87%8F%E5%8E%BB0.5%E9%99%A4%E4%B8%8E1%2F4%E7%9A%84%E5%95%86%2C%E5%B7%AE%E6%98%AF%E5%A4%9A%E5%B0%91%3F%E2%91%A2+%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97+1%2F5%C3%B712%2B4%2F5%C3%971%2F13%E2%91%A2+%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97+1%2F5%C3%B713%2B4%2F5%C3%971%2F13)
① 一个数,减去3.5与4的积,差是20的1/2,求这个数是多少?【列方程解答】② 2的倒数与2.5的和除与1/2的商,减去0.5除与1/4的商,差是多少?③ 简便运算 1/5÷12+4/5×1/13③ 简便运算 1/5÷13+4/5×1/13
① 一个数,减去3.5与4的积,差是20的1/2,求这个数是多少?【列方程解答】
② 2的倒数与2.5的和除与1/2的商,减去0.5除与1/4的商,差是多少?
③ 简便运算 1/5÷12+4/5×1/13
③ 简便运算 1/5÷13+4/5×1/13
① 一个数,减去3.5与4的积,差是20的1/2,求这个数是多少?【列方程解答】② 2的倒数与2.5的和除与1/2的商,减去0.5除与1/4的商,差是多少?③ 简便运算 1/5÷12+4/5×1/13③ 简便运算 1/5÷13+4/5×1/13
1、x-3.5*4=20*1/2
x-14=10
x=24
2、(1/2+2.5)÷1.2-0.5÷(1/4)
=3÷1.2-0.5×4
=2.5-2
=0.5
3、原式=1/5×1/12+(1-1/5)×1/13
=1/5×1/12+1/13-1/5×1/13
=1/5×(1/12-1/13)+1/13
=1/5×1/12×1/13+1/13
=(1/60+1)×1/13
=61/60×1/13
=61/780
1、x-3.5*4=20*1/2
x-14=10
x=24
2、(1/2+2.5)÷1.2-0.5÷(1/4)
=3÷1.2-0.5×4
=2.5-2
=0.5
3、原式=1/5×1/12+(1-1/5)×1/13
=1/5×1/12+1/13-1/5×1/13
=1/5×(1/12-1/13)+1/13
=1/5×1/12×1/13+1/13
=(1/60+1)×1/13
=61/60×1/13
=61/780追
咳!伦家飘~~飘过~~~