Answer:
Step-by-step explanation:
t1 = a1
t2 = a1 + d
t3 = a1 + 2d
The sum is t1 + t2 + t3 = a1 + a1 + d + a1 + 2d = 3a1 + 3d
Second question
t1 = a1
t2 = a1 + d
t3 = a1 + 2d
t4 = a1 + 3d
...
tn = a1 + (n - 1)*d
Sum = (a1 + a1 + (n- 1)*d) * n / 2
Sum = (2a1 + nd - d) * n / 2
Sum = (2a1*n + n^2*d - nd) / 2
Answer:
whole
Step-by-step explanation:
Answer: 12(5x - y)
Step-by-step explanation:
Set the function equal to ) and solve for x
x=10, 3
Answer:
Step-by-step explanation:
6x - 2y = 14
x = (14 + 2y)/6
--------------------------
y = 3(14 + 2y)/6 - 7
y = (14 + 2y)/2 - 7
2y = 14 + 2y - 14
2y - 2y = 14 - 14
