Answer:

Subtract 9 from both sides:


Multiply both sides by 2:


It's probably the first one: "People responded to Earth Day with letters..."
Since it's more of a detail that supports a fact, it's not as important as the other three.
Answer:
d=2
Step-by-step explanation:
3d + 6 = 12
first subtract 6 from both sides
3d=6
divide by 3 on both sides
d=2
Answer:
391
Step-by-step explanation:
17 x 23 = 391