Answer: 5.32 × 10^12
Step-by-step explanation:
This is a question relating to indices. In indices, we add the power given for question relating to multiplication. Hence, this will be:
= (2.8•10^8)(1.9•10^4)
= (2.8 × 1.9) × 10^8+4
= 5.32 × 10^12
Therefore, the answer to the question will be 5.32 × 10^12.
I hope this is right i think the answer is 40
Answer:
16) 62.8 m²
17) 19.4 m²
18) 103.5 m²
Step-by-step explanation:
The formula to find area of a circle is: 
. To find radius, find the half of the diameter.
To solve number 16, first find the area of the unshaded circle using the formula: 
. This is also 3.14*16. Multiply to get 50.24 m². Now find the area of the larger circle using the formula: 
. This is also 3.14*36. Multiply to get 113.04 m². Now subtract 113.04 - 50.24 to get the shaded area or 62.8 m².
To solve number 17, first find the area of the square using the formula: side x side. In this case multiply: 5.25 x 5.25 to get 27.5625. Round to the nearest tenth to get 27.6 m². Now find the area of the circle using the formula: 
. This is also 3.14*2.625. Multiply to get 8.2425. Round to the nearest tenth to get 8.2. Subtract 27.6 - 8.2 to get 19.4 m².
To solve number 18, find the area of one unshaded circle using the formula: 
. This is also 3.14*3.0625. Multiply to get 9.61625. Round to the nearest tenth to get 9.6 m². Add 9.6 + 9.6 to find the area of both unshaded circles. You get 19.2 m². Now find the area of the shaded circle using the formula: 
. This is also 3.14*39.0625. Multiply to get 122.65625. Round to the nearest tenth: 122.7. Subtract 122.7 - 19.2 to get 103.5 m².
Hope it helps and is correct!
