What i x ?

Question

5^x*5^3=625

pls show Working

Answer 1

(insert rant about people not even trying to do their own homework here).

5^x*5^3=625
divide by 5^3
5^x=5
Take the logarithm, base 5, of both sides:
x=1

Helpful tip: instead of posting homework problems and asking people to do them for you, try figuring out exactly what it is you don't understand and asking people to explain the concepts to you. That way, you will know how to do these problems come test time.

Edit: Wow, I didn't think that people could mess up such a simple problem, but apparently I was wrong.

Gnomon: 625/125 = 5, not 25.

rajniraniroy... I have no idea what's going on in your head, but note that:

the base is 5, not 25
a^x*a^y = a^(x+y), not a^(xy)

Answer 2

The key is write the problem out correctly. The ^ is done before the *, so....

5^x * 5^3 = 625 is the same as.....

( 5^x) * (5^3) = 625. They are testing to see if you know how to group things. Now it's a lot easier...

( 5^x) * (5^3) = 625

( 5^x) * 125 = 625 .....Because (5^3 = 5*5*5 = 5*25 = 125)

( 5^x) = 625 / 125 ....Divide both sides by 125

( 5^x) = 5 ......becasue 625/125 = 5

5 ^ x = 5 ^ 1 ....becasue 5 = 5 ^1

x = 1 ....becasue the two sides are exactly the same when x = 1

I hope that helps. Good Luck!

Answer 3

Taking log of both sides and remembering 625= 5^4

log5^3 + x*log5 = log5^4 ==> 3log5 +xlog5 = 4log5

dividing both sides by log5 3+x=4
x=1

Answer 4

Firstly, note that 5^3 is 5*5*5 which is125.

So 5^x*125 = 625

Divide both sides of your equation by 125.

Now you have:

5^x = 25

So what power of 5 is 25?

Answer 5

5^x*5^3 = 625
125*5^x = 625
5^x = 25
5^x = 5^2
x = 2

Answer 6

5^X*5^3=625
5^X8125=625
DEVIDNG BOTH SIDES BY 125
5^X=5

THIS IMPLIES
X=1

Answer 7

Ln5^x(ln5^3)=ln25^2, so x+3=2

Answer 8

5^x*5^3=625
25^3x=25^2
since base value is same -25
therefore 3x=2
x=2/3