Question #484ea

1 Answer
Mar 7, 2016

#x=(1+-sqrt65)/8=1.13#

Explanation:

#ln(x+4)=lnx^2+ln(4)#-> Use property #log_ba^x=xlog_ba#
#ln(x+4)=ln(4x^2)#->Use property #log_b(xy)=log_bx+log_by#
#ln(x+4)-ln(4x^2)=0#-> Put everything on one side
#ln((x+4)/(4x^2))=0#->Use property #log_b(x/y)=log_bx-log_by#
#10^0 = (x+4)/(4x^2)#-> use definition #y=logx iff 10^y=x#
#1=(x+4)/(4x^2)#
#4x^2=x+4#
#4x^2-x-4=0#
#x=(1+-sqrt(1-4(4)(-4)))/8#
#x=(1+-sqrt65)/8=1.13 or -0.88#