## anonymous 5 years ago solve 7.2x ― 65 = 0

1. anonymous

7.2x=65 x=65/7.2=9.028

2. anonymous

Hmm the problem that i had with this question is that the x is in the powers position in teh question (Attached file) ...does it mean teh same thing?

3. anonymous

sorry in question it doesn't look that like..

4. anonymous

ik thats why i posted pic

5. anonymous

$xln7.2=\ln65$ now please find the values

6. anonymous

$xln7.2=\ln65$ now please find the values

7. anonymous

x = 2.11....? i just ln both #'s in cal...and divided the two to solve for x....ik its wrong but idk how to do this..

8. anonymous

do u know the use of ln???

9. anonymous

hmm no...

10. anonymous

please go through the page http://en.wikipedia.org/wiki/Logarithm

11. anonymous

Your problem looms like this..$7.2^{x} -65=0$ Hence $7.2^{x}=56$ So take the log of both sides of the equation using your calculator (this will automatically be to base 10) $\log_{10}7.2^{x} =\log_{10} 65$ Then because of the laws of logorithms you can bring the power down to become the coefficient of the first term $x \log_{10} 7.2=\log_{10} 56$ Then divide the right by the left leaving x on the left hand side; $x=\log_{10}56/\log_{10} 7.2$ which equals 2.1146(4.D.P) you can check it equals x by raising 7 to this number - it gives 65.