求題中的未知量
1.x的百分增減是-16%,新值是84
2.y的百分增減是+30%,新值是52
3.u的百分增減是-88%,新值是10.2
4.d的百分增減是+70%,新值是20.4
要有過程
有數學唔識做？？
2007-04-15 11:10 am
回答 (3)
2007-04-15 11:20 am
✔ 最佳答案
1. x * (1- 16%) = 84
x * 84% = 84
x * 84 / 100 = 84
x / 100 = 1
x = 100
2.
y * (1 + 30%) = 52
y * 130% = 52
y * 130 / 100 = 52
y = 52*100/130
y = 40
3.
u * (1 - 88%) = 10.2
u * 12% = 10.2
u * 12 / 100 = 10.2
u = 10.2 * 100 / 12
u = 85
4.
d * (1 + 70%) = 20.4
d * 170% = 20.4
d * 170 / 100 = 20.4
d = 20.4 * 100 / 170
d = 12
2007-04-15 11:33 am
1. x(1-16%)=84
(84/100)x = 84 < 84%= 84/100= 0.84 >
x=100
2. y(1+30%) = 52
130%y = 52 < 130%= 130/100=1.3 >
y = 40
3. u(1-88%) = 10.2
12%u = 10.2 < 12%=12/100=0.12 >
u = 85
4. d(1+70%) = 20.4
170%d = 20.4 < 170% = 170/100=1.7 >
d = 12
我諗應該係咁計了...
(84/100)x = 84 < 84%= 84/100= 0.84 >
x=100
2. y(1+30%) = 52
130%y = 52 < 130%= 130/100=1.3 >
y = 40
3. u(1-88%) = 10.2
12%u = 10.2 < 12%=12/100=0.12 >
u = 85
4. d(1+70%) = 20.4
170%d = 20.4 < 170% = 170/100=1.7 >
d = 12
我諗應該係咁計了...
2007-04-15 11:24 am
x(1-0.16)=84
0.84x=84
x=100
y(1+0.3)=52
1.3y=52
y=40
u(1-0.88)=10.2
0.12u=10.2
u=85
d(1+0.7)=20.4
1.7d=20.4
d=12
0.84x=84
x=100
y(1+0.3)=52
1.3y=52
y=40
u(1-0.88)=10.2
0.12u=10.2
u=85
d(1+0.7)=20.4
1.7d=20.4
d=12
收錄日期: 2021-04-26 13:51:47
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