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Contents
Exponential Equations 1 2
|
Exponential Equations
Simultaneous Equations
 To
solve simultaneous exponential equations, we try to reduce the equations into
linear equations.
Given and
9x . 27y
= 1,
calculate the values of x and y.
22x
. 2-3(y+2) = 2-2
22x - 3y - 6 = 2-2
2x - 3y - 6 = -2
2x = 3y + 4 ------(1)
9x . 27y
= 1
32x . 33y = 1
32x + 3y = 30
2x + 3y = 0
x = -1.5y ------(2)
Substitute (2) into (1):
(-1.5y) = 3y + 4
y = -2/3
Substitute y = -2/3 back into (2):
x = -3/2 (-2/3)
= 1
Given y = kxn
- 5, y = 27 when x=2 and y = 507 when x = 4, find the values of the constants k
and n.
when y = 27, x
= 2,
27 = k (2n) - 5
k (2n)
=
32
------(1)
when
y = 504, x = 4
507 = k (4n) - 5
k (4n) =
512
------(2)
(2) / (1) :
(4/2)n = 16
2n = 24
n = 4
when n = 4,
k (24) = 32
16k = 32
k = 2
y = 2x4 - 5
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