22.4-4=18.4 18.4÷80%=23 23×3=69 答:这个数的3倍是69.
4/5-3/5=1/5 4/5+3/5=7/5 1/5÷7/5=1/7 答:商是1/7.
4X-4.5÷0.5=3.4
4X-9 =3.4
4X =12.4
X =3.1 答:商是3.1.
90×2/3=60 60÷75%=80 答:甲数是80.
320÷[1+(1-1/4)]
=320÷[1+3/4]
=320÷7/4
=1280/7 1280/7×3/4=960/7 答:甲数是1280/7,乙数是960/7.
25÷1/4=100 100×(1-1/4)
=100×3/4
=75 答:甲数是100,乙数是75.