Answer
a) 1.8$\times$10$^{-2}$
b) 1.14$\times$10$^{10}$
c) -5$\times$10$^{4}$
d) 1.3$\times$10$^{3}$
Work Step by Step
When adding/subtracting numbers in scientific notation, make sure that the values are in the same base-10 value, then add/subtract accordingly.
When multiplying/dividing numbers, you don't have to convert them into the same base-10 exponential value, but add/subtract the exponents as you multiply/divide the bases.