Question

1. what is $5.5 \times 10^{-3}$ as a decimal?

a. 0.55
b. 0.0055
c. 0.00055
d. 0.055

1. the combined area of two parks with areas of $4.5 \times 10^6$ square meters and $2.5 \times 10^6$ square meters in scientific notation is:

a. $8.0 \times 10^6$
b. $5.0 \times 10^5$
c. $6.0 \times 10^6$
d. $7.0 \times 10^6$

Explanation:

Question 1

Step1: Recall scientific notation to decimal

For \(a\times10^{-n}\), move the decimal of \(a\) \(n\) places to the left. Here, \(a = 5.5\), \(n=3\).

Step2: Move decimal

Moving decimal in \(5.5\) three places left: \(0.0055\)? Wait, no, wait, \(10^{-3}\) means \(1/1000\). So \(5.5\times10^{-3}=5.5\div1000 = 0.0055\)? Wait, no, the options: let's check again. Wait, maybe I misread the exponent. Wait the problem is \(5.5\times10^{-3}\)? Wait the options: a. 0.55, b. 0.0055? Wait the options given: a. 0.55, b. 0.0055, c. 0.00055, d. 0.055. Wait, \(5.5\times10^{-3}\) is \(5.5\) divided by \(10^3=1000\), so \(5.5\div1000 = 0.0055\), which is option b? Wait no, wait the original problem: is it \(5.5\times10^{-3}\) or \(5.5\times10^{-4}\)? Wait the user's image: "What is \(5.5\times10^{-3}\) as a decimal?" Wait options: b is 0.0055, d is 0.055, a is 0.55, c is 0.00055. So \(5.5\times10^{-3}=0.0055\), so option b? Wait no, wait \(10^{-3}\) is 0.001, so 5.5*0.001=0.0055, yes. So step1: understand \(10^{-n}\) means moving decimal n places left. Step2: 5.5 with decimal moved 3 places left: 0.0055.

Step1: Add the two areas

The two areas are \(4.5\times10^{6}\) and \(2.5\times10^{6}\). Since they have the same exponent, we add the coefficients: \(4.5 + 2.5=7.0\).

Step2: Keep the same power of 10

So the combined area is \(7.0\times10^{6}\) square meters.

Answer:

b. 0.0055

Question 2