Answer:
a₁ = 38
Step-by-step explanation:
Given AP, where:
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<h3>Solution</h3>
aₙ = a₁ + (n-1)d
- a₈ = a₁ + 7d = a₁ + 7*(-2) = a₁ - 14
- a₁₂ = a₁ + 11d = a₁ + 11*(-2) = a₁ - 22
8a₈ = 12a₁₂
- 8(a₁ - 14) = 12(a₁ - 22)
- 2(a₁ - 14) = 3(a₁ - 22)
- 2a₁ - 28 = 3a₁ - 66
- 3a₁ - 2a₁ = -28 + 66
- a₁ = 38
Step-by-step explanation:
You said the other one would be the last haha just kidding I'm glad to help.
16. 
First, get rid of that parenthesis.

Now multiply both sides by 2 so that you can isolate k


19. 
This is a pretty easy one. If you didn't know, 121/11 is actually 11 :)

Simply multiply by 3 to isolate r :)

