7 Solve each equation GIVE EXACT ANSWERS no decimals a log x
7) Solve each equation. GIVE EXACT ANSWERS (no decimals.
a) log x = - 3 d) log x 5= 1/3
b) log x 1/11 = 1/2 e) log7/3 9/49=x
c) log 8 x = -3/2 f) e ln 13 = x
Solution
7.a log x=-3
We have to use the following property
If log a=b,then a=10b
Therefore we get
x=10-3=1/1000
b. logx(1/11)=1/2
1/11 =x1/2
x=1/121
logx=11/2
x=1011/2
c. log8x=-3/2
x= 8-3/2
d.logx5=1/3
5=x1/3
x=53=125
e.log7/3(9/49)=x
9/49= (7/3)x
(7/3)-2=(7/3)xx=-2
f. eln 13=x
x=13
