Answer:
10 friends
Step-by-step explanation:
we know that
The formula of the sum is equal to
![sum=\frac{n}{2}[2a1+(n-1)d]](https://tex.z-dn.net/?f=sum%3D%5Cfrac%7Bn%7D%7B2%7D%5B2a1%2B%28n-1%29d%5D)
where
a1 is the first term
n is the number of terms (number of friends)
d is the common difference in the arithmetic sequence
In this problem we have
----> the common difference
substitute in the formula and solve for n
![275=\frac{n}{2}[2(5)+(n-1)(5)]](https://tex.z-dn.net/?f=275%3D%5Cfrac%7Bn%7D%7B2%7D%5B2%285%29%2B%28n-1%29%285%29%5D)
![550=n[10+5n-5]\\ \\550=10n+5n^{2} -5n\\ \\5n^{2}+5n-550=0](https://tex.z-dn.net/?f=550%3Dn%5B10%2B5n-5%5D%5C%5C%20%5C%5C550%3D10n%2B5n%5E%7B2%7D%20-5n%5C%5C%20%5C%5C5n%5E%7B2%7D%2B5n-550%3D0)
Solve the quadratic equation by graphing
The solution is n=10
see the attached figure
therefore
She had 10 friends who got stickers
Answer:
she used distributive property
Step-by-step explanation:
What she did 5x3 then 5x4
Answer:
y = -2x^2 -4x +5
Step-by-step explanation:
The vertex is at (-1,7) and the y intercept is at (0,5)
The vertex form of a parabola is
y = a(x-h)^2 +k
where (h,k) is the vertex
y = a(x--1)^2 +7
Then substitute the point into the equation
y = a(x+1)^2 +7
5 = a(0+1)^2 +7 +7
Subtract 7 from each side
5-7 = a(1)^2
-2 = a
y = -2(x+1)^2 +7
Now FOIL
y = -2 (x^2 +2x+1) +7
Then distribute
y = -2x^2 -4x-2 +7
y = -2x^2 -4x +5
Answer:
50, 60, 70
Step-by-step explanation:
The mode is the value that appears the most:
2 50s
2 60s
1 80s
2 70s
1 55s
1 85s
1 90s
The modes are 50, 60, and 70
Answer:
Senior citizen ticket = $4, student ticket = $6
Step-by-step explanation:
To do this, form a system of equations where x = the cost for a senior citizen ticket and y = the cost for a student ticket.
Since 12 senior citizen tickets and 14 students tickets cost $132, you get
12x + 14y = 132.
Since 12 senior citizen tickets and 10 students tickets cost $108, you get
12x + 10y = 108.
You can subtract those two equations, so
12x + 14y = 132
-(12x + 10y = 108)
and you get
4y = 24
divide both sides by 4
y = 6
substituting into the equation 12x + 10y = 108,
12x + 10(6) = 108
12x + 60 = 108
subtract 60 from both sides
12x = 48
divide both sides by 12
x = 4
A senior citizen ticket costs $4 and a student ticket costs $6.
