Question

If x square +y square =23xy, then 2log (x+y)=
a. Iog x + log y
b. log x +log y +2log 5
c. log x - log y + log 5
d. log x + log y - log 5

Answer 1

Answer:

x square+y square=23xy

Add 2xy on both sides

x square + y square +2xy =23xy + 2xy

x square+y square+2xy =25xy

(x+y) square = 25xy

Add log on both sides

log (x+y) square =log 25xy

2log (x+y)= logx+logy+log 25 (logxyz=logx+logy +log25)

2log(x+y) = logx+ logy +log5 square

2log(x+y) =logx+logy +2log5

so answer is (b)