Answer:
y = - 2x + 7
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m =
with (x₁, y₁ ) = (8, - 9) and (x₂, y₂ ) = (- 4, 15)
m = =
= - 2, thus
y = - 2x + c ← is the partial equation
To find c substitute either of the 2 points into the partial equation
Using (8, - 9), then
- 9 = - 16 + c ⇒ c = - 9 + 16 = 7
y = - 2x + 7 ← equation of line
Answer:
120
Step-by-step explanation:
Since we're dealing with a problem where the order matters and the first two letters are already chosen we need to subtract the number of letters and the number of available slots per group.
We use the permutation formula to find the answer, but before that let's check values.
n = 8
k = 5
Now since there are two letters already chosen we have to deduct two from both the value of n and k.
n = 6
k = 3
Now we can use the permutation formula:
The 3*2*1 cancels out and leaves us with:
So there are 120 possible ways to arrange eight letters into groups of five where order matters and the first two letters are already chosen.