Question

Please, help me to solve this problems by Cramer rule

Question number :
1. 5/x + 3/y = 19
2/x + 1/y = 7

Question number :
2. log x + 2 log y = 4
2 log x - 3 log y = 1

so confuse..

Answer 1

#1. Do it as usual, but you will be solving for 1/x and 1/y.

D = -1
Dx = -2
Dy = -3

So, 1/x = Dx/D = 2, 1/y = Dy/D = 3
x = 1/2, y = 1/3

Same thing, but you are solving for logx and logy:

D = -5
Dx = -14
Dy = -3

logx = 14/5
logy = 3/5
x and y depend on the base of the logs.