Question

Solve for x and y in the equation.
xy=80 and log x - 2 log y =1

Answer 1

9514 1404 393

Answer:

(x, y) = (40, 2)

Explanation:

Taking the antilog of the second equation, we have ...

x/y^2 = 10

x = 10y^2

Substituting this into the first equation gives ...

(10y^2)y = 80

y^3 = 8 . . . . . . . . divide by 10

y = 2 . . . . . . . . . . cube root

x = 10·2^2 = 40

The solution is (x, y) = (40, 2).