Step-by-step explanation:
t8 = a1 + (n - 1)*d
t8 = 17
17 = a1 + 7*d
t12 = 25
25 = a1 + 11d
17 = a1 + 7d Subtract
8 = 4d Divide by 4
8/4 = 4d/4
2 = d
17 = a1 + 7d
17 = a1 + 7*2
17 = a1 + 14 Subtract 14
3 = a1
Sum 20 terms
The 20 term = a1 + 19*2
The 20 term = 3 + 38
= 41
Sum = (a1 + a20) * 20 / 2
Sum = (3 + 41)* 20/2
Sum = 44 * 10
Sum = 440
Answer:
the answer is 39
Step-by-step explanation:
hope that helps
Answer:
x=4.2
Step-by-step explanation:
7.8x = 32.76
/7.8 /7.8
x=4.2
The slope is a 2
here the stpes
6/3 got 2
y2-ya
x2-x1
then you get 6/3 devide ad that you slope