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:
Option 2) When the x-value is 0, the y-value is 1.
Step-by-step explanation:
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form 
or 
In a proportional relationship the constant of proportionality k is equal to the slope m of the line <em>and the line passes through the origin
</em>
Remember that in a direct variation
For x=0, the value of y is equal to zero too
therefore
The graph is not a direct variation , because
When the x-value is 0, the y-value is 1.
Answer:
(x1,y1) = (2x - x2, 2y - y2)
Step-by-step explanation:
Given:
Midpoint = (x , y)
End point = (x2, y2)
Find:
(x1, y1)
Computation:
Mid-point formula
x = (x1 + x2) / 2 , y = (y1 + y2) / 2
So,
2x = x1 + x2 , 2y = y1 + y2
x1 = 2x - x2 , y1 = 2y - y2
So,
(x1,y1) = (2x - x2, 2y - y2)
F(-1) = 3
How did I figure this out?
f(-1) is substituted for f(x) so you must look at -1 on the x axis.
Once you've located -1 on the x-axis, locate what it equals to answer the question.
The answer should be the y-axis number that corresponds to -1 which is 3.
