Yes, I believe the points are indeed correct.
L=7+w
P=(12x+14)=2(6x+7)
l+w= P/2 = 2(6x+7)/2= 6x+7
l+w=6x+7
2l = 6x+7
l = (6x+7)/2
l=7+w
-> w= l-7
= [(6x+7)/2] -7
= (6x+7-14)/2
= (6x-7)/2
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.
