Question

Which expression is equal to 5.1 × 10−3
?(1 point)
Responses

3.9 × 10−3 + 1.2 × 10−3
3.9 × 10−3 + 1.2 × 10−3

2.9 × 10−3 + 1.2 × 10−3
2.9 × 10−3 + 1.2 × 10−3

3.5 × 103 + 1.6 × 10−6
3.5 × 103 + 1.6 × 10−6

2.2 × 10−1 + 2.9 × 10−2

Answer 1

To determine which expression is equal to \( 5.1 \times 10^{-3} \), we need to evaluate each option.

1. **Option 1:** \( 3.9 \times 10^{-3} + 1.2 \times 10^{-3} \)
\[
3.9 \times 10^{-3} + 1.2 \times 10^{-3} = (3.9 + 1.2) \times 10^{-3} = 5.1 \times 10^{-3}
\]

2. **Option 2:** \( 2.9 \times 10^{-3} + 1.2 \times 10^{-3} \)
\[
2.9 \times 10^{-3} + 1.2 \times 10^{-3} = (2.9 + 1.2) \times 10^{-3} = 4.1 \times 10^{-3}
\]

3. **Option 3:** \( 3.5 \times 10^{3} + 1.6 \times 10^{-6} \)
\[
\text{This expression has a different order of magnitude since } 3.5 \times 10^{3} \text{ is much larger than } 10^{-3}.
\]

4. **Option 4:** \( 2.2 \times 10^{-1} + 2.9 \times 10^{-2} \)
\[
2.2 \times 10^{-1} + 2.9 \times 10^{-2} = 0.22 + 0.029 = 0.249 \text{ which is } 2.49 \times 10^{-1}.
\]

From our evaluations, the only expression equal to \( 5.1 \times 10^{-3} \) is:

**Response:** \( 3.9 \times 10^{-3} + 1.2 \times 10^{-3} \)