P + s = 200......p = 200 - s
20p + 15s = 3400
20(200 - s) + 15s = 3400
4000 - 20s + 15s = 3400
-20s + 15s = 3400 - 4000
-5s = - 600
s = -600/-5
s = 120 <=== there were 120 standard tickets sold
p + s = 200
p + 120 = 200
p = 200 - 120
p = 80 <=== there were 80 premium tickets sold
126 students like football :)
Answer: the system has no solution.
Step-by-step explanation:
\displaystyle\\
\left \{ {{x^2y=16\ \ \ \ \ (1)} \atop {x^2+4y+16=0\ \ \ \ \ (2)}} \right. .\\
Multiply\ both\ sides\ of\ the\ equation\ (2)\ by\ y\ (y\neq 0):\\
x^2y+4y^2+16y=0\\
We\ substitute\ equation\ (1)\ into\ equation\ (2):\\
16+4y^2+16y=0\\
4y^2+16y+16=0\\
4*(y^2+4y+4)=0\\
4*(y^2+2*y*2+2^2)=0\\
4*(y+2)^2=0\\
Divide\ both\ sides\ of\ the \ equation\ by\ 4:\\
(y+2)^2=0\\
(y+2)*(y+2)=0\\
So,\ y+2=0\\
y=-2.\\

Answer:
no mode
The median and mode are 12
Step-by-step explanation:
The mode is the number that appears most often
Since no number repeats there is no mode
The mean is the average
Add up all the numbers
(12+12+12+12+13+13+15)/7 = 89/7 = 12 5/7
The median is the middle number
There are 7 numbers
7/2 = 3.5
The 4th number is the median
The 4th number is 12
The mode is the number that appears most often which is 12
Answer:
x⁴ - 8x² + 9
Step-by-step explanation:
The Area of the smallest square is A1 = x . x = x²
The Area of the second square is A2 = ( x² - 3 )(x² - 3)
A2 = x⁴ - 3x² - 3x² + 9
A2 = x⁴ - 6x² + 9
The Area of the Shaded shape is A2 - A1
x⁴ - 6x² + 9 - x²
x⁴ - 8x² + 9