Answer:
Sum of the first 15 terms = -405
Step-by-step explanation:
a + 3d = -15 (1)
a + 8d = -30 (2)
Where,
a = first term
d = common difference
n = number of terms
Subtract (1) from (1)
8d - 3d = -30 - (-15)
5d = -30 + 15
5d = -15
d = -15/5
= -3
d = -3
Substitute d = -3 into (1)
a + 3d = -15
a + 3(-3) = -15
a - 9 = -15
a = -15 + 9
a = -6
Sum of the first 15 terms
S = n/2[2a + (n − 1) × d]
= 15/2 {2×-6 + (15-1)-3}
= 7.5{-12 + (14)-3}
= 7.5{ -12 - 42}
= 7.5{-54}
= -405
Sum of the first 15 terms = -405
Answer:
A farmer keeps a record of the weekly milk yield of his herd of seven cows over a period of six months. He finds that the mean yield is 24 liters. He buys another cow that he is told will produce 28 liters of milk a week. Work out the effect this will have on the mean milk yield of his cows.
Step-by-step explanation:
Hope it helps<3
The slope would be (3-1)/(6-4) or 1
Answer:
Slope = -3
Step-by-step explanation:
Slope intercept form: y = mx + b (where m is the slope).
Our line is parallel to y = -3x + 4. Since it's parallel, it will have the same slope.
