係公式移主項(色幾多答幾多 唔該哂各位!)

1/y = (x-1)/(x+1) +1/z
(x+1)/y = (x-1) + (x+1)/z
x/y -x/z - x = 1/z-1/y-1
x = (1/z-1/y-1)/(1/y-1/z-1)

l=(n-2)180/n
nl = 180n-360
360 = 180n-nl
n=360/(180-l)

p=(3v-rt)/(4t+v)-1
p+1 = (3v-rt)/(4t+v)
4pt+pv+4t+v = 3v-rt
pv+v-3v=-rt-4pt-4t
t=v(p-2)/(-r-4p-4)
t=v(2-p)/(r+4p+4)

第1題.. 唔可以就咁將分子分母倒轉.. 呢d要通左分母先
1/y = (x-1)/(x+1) + 1/z
xz + z = xyz - yz + xy +y
xz - xyz - xy = y - yz - z
(z - yz - y) x = y - yz - z
x = (y-yz-z)/(z-yz-y)

第2題
I = (n-2)180 /n
nI = (n-2)180
nI = 180n - 360
360 = 180n - nI
n = 360 / (180-I)

第3題
題目係想你將主項變做t... 用p,r,v表示
p = (3v - rt)/(4t + v) - 1
p = [3v - rt - (4t + v)]/(4t + v)
(4t + v)p = 3v - rt - 4t - v
4pt + vp = 2v - rt - 4t
4pt + rt + 4t = 2v - vp
(4p + r + 4)t = 2v - vp
t = (2v - vp) / (4p + r + 4)