Solve for $x$:$-15lb**5ft10l{b}^{**}6ft=9f{t}^{**}x$

Solve for $x$:$15l\frac{b}{x}=3lb12lb$

Solve for $P$:$,250mm(11\mathrm{.}7\frac{{10}^{-6}}{C})50C-\frac{P(250(mm))}{707m{m}^2(200{10}^3\frac{(N)}{m{m}^2})}=\frac{P(300(mm))}{1963m{m}^2(105{10}^3\frac{(N)}{m{m}^2})}-300mm(20\mathrm{.}9\frac{{10}^{-6}}{C})50C$

Write ${1\mathrm{.}315}^{**}{10}^{-4}$ as a number multiplied by ${10}^{-3}.$

Write $500**{10}^8$ as a number multiplied by ${10}^9.$