Question

求1/2log(10)(x+6)加log(10)(根号2x+5)=log(10)(6根号2）

Answer 1

1/2log(10)(x+6)加log(10)(根号2x+5)=log(10）(6根号2);

lg[根号(x+6)]+lg[根号(2x+5)]=lg根号72;

lg[根号(x+6)]*[根号(2x+5)]=lg根号72;

[根号(x+6)]*[根号(2x+5)]=根号72;

(x+6)*(2x+5)=72;

2x^2+17x-42=0;

;x=2;x=-21/2(x+6