Answer:x=24
Step-by-step explanation:x/2-8=4
Add 8 to both sides
x/2=12
Multiply each side by 2
x=24
Answer:
480
Step-by-step explanation:
Sn = n÷2 × (2a + (n-1)d)
n = 20 a = -14 d = 4
S20 = 10 × (-28 + 19 × 4) = 480
Answer:
24?
Step-by-step explanation:
I'm not very good at math and I'm sorry if I'm wrong.