50,000 is the answer because if you multiply 5,000 and 10 you get 50,000. And if you divide 50,000 by 10 you get 5,000. Which is 1/10 of 50,000.
assuming you means k = log_2(3) [as log(2)3 is the same thing as 3log(2) due to multiplication being commutative]
given log(ab) = log(a) + log(b)
log_2(48) = log_2(3) + log_2(16)
<u>answer:</u> 
<u>work:</u>
| subtract 5x and move it over to the 7x, and solve
| subtract 4 and move it over to the 10, and solve
| divide by 2
| final answer
hope this helps! ❤ from peachimin
3x=4y
x+y=21
x = 21-y
3(21-y)=4y
63-3y=4y
63=7y
y=9
x+y=21
x+9=21
x=12
answer is (12, 9)