36-x+16=25如何解方程?

问题描述:

36-x+16=25如何解方程?

36-X=9

3×16^x+36^x=2×81^x
3×(16/81)^x+(36/81)^x=2
3×(16/81)^x+(4/9)^x=2
不妨设t=(4/9)^x(t>0)
则3t^2+t-2=0
(t+1)(3t-2)=0
∵t>0
∴t=2/3
∴(4/9)^x=2/3
∴x=1/2
∴经检验,x=1/2是原方程的实数根

36+16-25=x
x=-5

x=36+16-25=27

36-X=9
X=36-9
X=27

x=36+16-25
x=27

36-x=9
x=27

36-x+16=25
52-x=25
52-25=x
x=27

x = 36+16-25
= 27