My sister and I have a bet on my homework

The length of a rectangle is 1.2 x10-4 kilometer. The width of the rectangle is 6.25x10^-5 kilometer. What is the area in square kilometers of this rectangle?
7.5x10-9 or 7.5x10^3

(1.2 * 10^-4 km)(6.25*10^-5 km) = 7.5*10^-9 km^2

that's 7.5*10^-3 m^2

To find the area of a rectangle, you multiply the length by the width.

Given:
Length = 1.2 x 10^-4 kilometer
Width = 6.25 x 10^-5 kilometer

Let's calculate the area step by step:

Step 1: Multiply the length and the width

(1.2 x 10^-4) km * (6.25 x 10^-5) km

Step 2: Multiply the coefficients (1.2 * 6.25)

= 7.5

Step 3: Multiply the powers of 10 (-4 * -5)

= 10^-9

So, the area of the rectangle is 7.5 x 10^-9 square kilometers.

To find the area of a rectangle, we need to multiply the length by the width. In this case, the length is given as 1.2 x 10^-4 kilometer and the width is given as 6.25 x 10^-5 kilometer.

To multiply two numbers expressed in scientific notation, we multiply their coefficients (1.2 * 6.25) and then add the exponents (-4 + -5).

(1.2 * 6.25) = 7.5

(-4 + -5) = -9

Therefore, the area of the rectangle is 7.5 x 10^-9 square kilometers. So you win the bet!