<span>Remember that it's against our guidelines to copy content from other websites, books or any other material to which you don't own the rights to. We know you have the power to solve these problems on your own</span>
Remember property of exponents

add exponents of same base
ok so
50,000 is 5 times 10^4
so
50000 times 10^15=
5 times 10^4 times 10^15=
5 times

=
5 times 10^19
Subtract 4 from each side
Divide both sides by 5
Take square root of both sides
Add 3 to both sides