Question #27c70

1 Answer
Jan 22, 2017

#x≈4.090" to 3 dec. places"#

Explanation:

Isolate the exponential by dividing both sides by 40

#rArr(1.5)^x=210/40=21/4#

#color(orange)"Reminder " color(red)(bar(ul(|color(white)(2/2)color(black)(logx^n=nlogx)color(white)(2/2)|)))#

Take the ln ( natural log) of both sides.

#rArrln(1.5)^x=ln(21/4)#

#rArrxln(1.5)=ln(21/4)#

#rArrx=(ln(21/4))/(ln1.5)≈4.090" to 3 dec.places"#