公式~~~~~~

因式分解o個題唔明你打乜.....

1. a = (p + t) / (s - t) [t]
a(s - t) = p + t
as - at = p + t
t + at = p - as
t(1 + a) = p - as
t = (p - as) / (a + 1)

2. ab + c(b + 1) = a [a]
ab + bc + c = a
a - ab = bc + c
a(1 - b) = bc + c
a = [c(b + 1)] / (1 - b)

3. x/a + 1/(y - b) = 1/a [b]
1 / (y - b) = 1/a - x/a
1/(y - b) = (1 - x) / a
(y - b)(1 - x) = a
y - xy - b + bx = a
bx - b = a + xy - y
b(x - 1) = a + xy - y
b = (a + xy - y) / (x - 1)

4. x = [(5 - 2y) / (y - 1)] + 3 [y]
x - 3 = (5 - 2y) / (y - 1)
(x - 3)(y - 1) = 5 - 2y
xy - x - 3y + 3 = 5 - 2y
xy - 3y + 2y = 2 + x
xy - y = x + 2
y(x - 1) = x + 2
y = (x + 2) / (x - 1)

(x+y)二次方

------------------ - x (x+y)

...... 2



變換主項:

1.



.... p + t (要t為主項)

a= ------

.. .. s- t



2.



ab+c(b+1)=a (要b為主項 )



3.



x ...... . 1 ... . .. 1

-- + -------- = ----- (要b為主項 )

a ..... y - b . . .. a



4.

...... 5 - 2 y

x = --------- + 3 (要y為主項 )

......... y-1

(x+y) (x+y)

------------------ - x (x+y)

.......... .2

0.(x+y)²

-------------- - x (x+y)

.......2



=2*((x+y)²

-------------- - x (x+y))

.........2



=(x+y)²-2x(x+y)



=(x+y)[(x+y)-2x]



=(x+y)(y-x)



1. a = (p + t) / (s - t) [t]



a(s - t) = p + t



as - at = p + t



t + at = p - as



t(1 + a) = p - as



t = (p - as) / (a + 1)



2. ab + c(b + 1) = a [a]



ab + bc + c = a



a - ab = bc + c



a(1 - b) = bc + c



a = [c(b + 1)] / (1 - b)







3. x/a + 1/(y - b) = 1/a [b]



1 / (y - b) = 1/a - x/a



1/(y - b) = (1 - x) / a



(y - b)(1 - x) = a



y - xy - b + bx = a



bx - b = a + xy - y



b(x - 1) = a + xy - y



b = (a + xy - y) / (x - 1)







4. x = [(5 - 2y) / (y - 1)] + 3 [y]



x - 3 = (5 - 2y) / (y - 1)



(x - 3)(y - 1) = 5 - 2y



xy - x - 3y + 3 = 5 - 2y



xy - 3y + 2y = 2 + x



xy - y = x + 2



y(x - 1) = x + 2



y = (x + 2) / (x - 1)