Question

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

3.5×103+1.6×10−6
3.5 times 10 cubed plus 1.6 times 10 superscript negative 6 baseline

2.9×10−3+1.2×10−3
2.9 times 10 negative cubed plus 1.2 times 10 negative cubed

3.9×10−3+1.2×10−3
3.9 times 10 negative cubed plus 1.2 times 10 negative cubed

2.2×10−1+2.9×10−2

Answer 1

To find which expression is equal to \( 5.1 \times 10^{-3} \), let's evaluate each response:

1. \( 3.5 \times 10^{3} + 1.6 \times 10^{-6} \)
- This expression has \( 3.5 \times 10^{3} \), which is much larger than \( 10^{-3} \), so it will not equal \( 5.1 \times 10^{-3} \).

2. \( 2.9 \times 10^{-3} + 1.2 \times 10^{-3} \)
- Combine the terms:
\[
2.9 \times 10^{-3} + 1.2 \times 10^{-3} = (2.9 + 1.2) \times 10^{-3} = 4.1 \times 10^{-3}
\]
- This does not equal \( 5.1 \times 10^{-3} \).

3. \( 3.9 \times 10^{-3} + 1.2 \times 10^{-3} \)
- Combine the terms:
\[
3.9 \times 10^{-3} + 1.2 \times 10^{-3} = (3.9 + 1.2) \times 10^{-3} = 5.1 \times 10^{-3}
\]
- This equals \( 5.1 \times 10^{-3} \).

4. \( 2.2 \times 10^{-1} + 2.9 \times 10^{-2} \)
- Convert \( 2.2 \times 10^{-1} \) to \( 0.22 \) and \( 2.9 \times 10^{-2} \) to \( 0.029 \):
\[
0.22 + 0.029 = 0.249
\]
- In scientific notation, \( 0.249 = 2.49 \times 10^{-1} \), which does not equal \( 5.1 \times 10^{-3} \).

Thus, the correct expression that is equal to \( 5.1 \times 10^{-3} \) is:

**3.9×10−3+1.2×10−3**