A question: (5.3 x 10 to the 6th power) + 8.2 10 to the 6th power) A solution: Multiply 10 x 10 6 times to get rid of the two powers. (5.3 x 1,000,000) + (8.2 x 1,000,000) Multiply inside the parenthises. (5,300,000) + (8,200,000) Add: 13,500,000. A answer: 13, 500,000.
B question: (6.5 x 10 to the 7th power) / (5 x 10 to the 3rd power) B solution: Again, get rid of the powers. (6.5 x 10,000,000) / (5 x 1,000) Multiply inside the parenthesis: (65,000,000) / (5,000) Divide: 13,000 B answer: 13,000.
C question: (4.6 x 10 to the 6th power) (3 x 10 to the 5th power) / (2 x 10 to the 7th power) C solution: Get rid of powers: (4.6 x 1,000,000) (3 x 100,000) / (2 x 10,000,000) Multiply: (4,600,000) (300,000) / (20,000,000) multiply in the left side: (1,380,000,000,000) / (20,000,000) divide: 69,000 C answer: 69,000
first you take 1/6th of the original 90 copies which is 15 and subtract that from the 90, you are left with 75 copies which is how many they had left at the end of yesterday. then you take 1/5th of the 75 copies that are left which is also 15 and you subtract that from 75 and you get 60. that's why at the end of today there are 60 copies left.
The way to get the equation for the radius (r) is to get r by itself. So divide each side by 4pi 500/4pi=r^2 Now take the square root of each side to get the equation of r. sqrt(500/4pi)=r
