3^(x-y)/3^(y-x) +3^(2xy)=90
Solve x and y. Also show your steps.
更新1:
二元方程
數學方程式, 求解
2010-02-17 3:38 am
2^(x+y)+2^(2x-y)=16
3^(x-y)/3^(y-x) +3^(2xy)=90
Solve x and y. Also show your steps.
3^(x-y)/3^(y-x) +3^(2xy)=90
Solve x and y. Also show your steps.
回答 (1)
2010-02-27 12:55 am
✔ 最佳答案
2^(x+y)+2^(2x-y)=16 = 2^3 + 2^3x + y = 3......(1)
2x - y = 3......(2)
(1)+(2) :
3x = 3+3
x = 2
y = 1
3^(x-y)/3^(y-x) +3^(2xy)=90
[3^(x-y)][3^(x-y)] + 9^(xy) = 90
9^(x-y) + 9^(xy) = 90
when x = 2 and y = 1 :
9^(2-1) + 9^(2*1) = 9 + 81 = 90
so x = 2 and y = 1 for both equations
收錄日期: 2021-04-21 22:10:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100216000051KK00989