Answer:
-46
Step-by-step explanation:
We need to find the common difference of this arithmetic sequence:

So, the common difference d = -4. We can now write the equation:


So, the 15th term is -46.
Hope this helps!
Your answer would be A b=a+5
Answer:
a = -12
Step-by-step explanation:
3a – 5(a - 2) = 34
→ Expand out the brackets – 5(a - 2)
– 5(a - 2) = – 5(a + 2) = -5a + 10
→ Substitute that back into the equation
3a - 5a + 10 = 34
→ Simplify the 'a's
-2a + 10 = 34
→ Minus 10 from both sides to isolate -2a
-2a = 24
→ Divide both sides by -2 to isolate a
a = -12