两个方程求解x与y

由(1)得
2^2x ×2^y=2^4
∴2x+y=4
x=(4-y)/2 (3)
由(2)得 2^x×3^y=2×3
∴2^(x-1)=3^(1-y)
x-1=(1-y)log2 3 (4)
(3)代入(4)得
(4-y)/2-1=(1-y)log2 3
4-y-2=2(1-y)log2 3
2-y=2log2 3 -2ylog2 3
(2log2 3-1)y=2log2 3 -2
y=(2lg3-2lg2)/(2lg3-lg2)
把y=(2lg3-2lg2)/(2lg3-lg2)代入(3)得
x=2-(lg3-lg2)/(2lg3-lg2)
x=(3lg3-lg2)/(2lg3-lg2)

4^x*2^y=16
2^2x*2^y=16
2^(2x+y)=16
∴2x+y=4
y=4-2x
2^x+3^(4-2x)=6

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4^x * 2^y = 16，2^2x * 2^y = 16，2^(2x+y) = 2^4，2x+y = 4, y = 4-2x=2(2-x),
2^x * 3^y = 6，2^x * 3^2(2-x) = 6，2^x * 9^(2-x) = 6，2^x * 9^2/9^x = 6，
(2/9)^x = 6/9^2...