數學－代入法

1)H = 4 / m - n

H = 4 / m - n
H=(4/0.5)-7
H=8-7
H=1
-------------------------------------------------------------------------------------------------------
2)T = ( P - 1 ) / V

T = ( P - 1 ) / V
6=(3-1)/V
6=2/V
V=2/6
V=1/3
-------------------------------------------------------------------------------------------------------
3)A = P ( 1 + R )T次方

A = P ( 1 + R )T次方
1440=P(1+20%)²
1440=P(6/5)²
1440=P(36/25)
P=1440 x 25 / 36
P=1000
-------------------------------------------------------------------------------------------------------
4)V = 1 / 3 ( h + 3 )

V = 1 / 3 ( h + 3 )
40=1/3(h+3)
(1/3)h+1=40
(1/3)h=40-1
(1/3)h=39
h=39 x 3
h=117

Ｑ１）如果 m = 0.5 , n = 7 ,求 H.
　　　H = 4 / m - n
H = 4/0.5-7
H = 8-7
H = 1

Ｑ２）如果 T = 6 , P = 3 , 求 V.
　　　T = ( P - 1 ) / V
6=(3-1)/ V
6=2/V
V=0.33333333333.....................
Ｑ３）如果 A = 1440 , R = 20 % , T = 2 , 求 P.
　　　A = P ( 1 + R )T次方
1440=P(1+20%)2
1440=P(120%)2
P=1
Ｑ４）如果 V = 40 , a = 60 , b = 4 , 求 h.
　　　V = 1 / 3 ( h + 3 )
好似冇左a喎~

你只要把相對的未知數的值代入數式中 , 便可求出答案了 !
Ｑ１）如果 m = 0.5 , n = 7 ,求 H.
　　　H = 4 / m - n

H = 4 / 0.5 - 7
if H = ( 4 / 0.5 ) - 7
H = 8 - 7
H = 1
if H = 4 / ( 0.5 - 7 )
H = 4 / -6.5
H = -0.615 ( 準確至小數後三個位 )


其餘三題的做法大同小異 , 不妨自己試試看 ! 努力吧 !
圖片參考：http://hk.yimg.com/i/icon/16/35.gif