Answer:
a) x-4+9
b) x-2
For part b, I am not 100% sure about my answer, but I am sure about part a.
100 it's like the absolute value
You just add the LxW and for area you multiply LxWxLxW
Step-by-step explanation:
2 × 10⁸ - 7 × 10⁷
= 200,000,000 - 70,000,000
=130,000,000
= 1.3 × 10⁸