Okay, so keeping mind that the equation for area is A = L x W, look at the measurements you already have. 5.5 x 10^5 is the length, and 4.2 x 10^4 is the width. Switch them into full form and use a calculator to multiply the two for the area in meters.
550000 x 42000 = 23100000000, which in scientific form is 2.31 × 10^10. So that's answer one.
For the second, in kilometers, just take the full measurement you already have, 23100000000 m, transfer it into kilometers, 23100000 km, and then find its scientific notation, 2.31 × 10^7. That's answer two.
To answer the last question for which is more suitable, just consider what number you'd prefer to look at: a bigger number or a smaller one. Since the kilometer measurement number is smaller, its correct.
Summarily, the answers are 2.31 × 10^10, 2.31 × 10^7, and square kilometers, in that order.
It’s 18x because 36 and 54 are both divisible by 18, and 18 can be divisible by 18 (making 1), resulting in 18 being the most common number between the numbers, whereas the ‘x’ is common between all 3 numbers and since the least amount of x is 1, the answer is just x without an exponent
