I don't understand what you mean by 'mentally' but anyways, here is how to solve it.
(z−12)(z+12)
=(z+−12)(z+12)
=(z)(z)+(z)(12)+(−12)(z)+(−12)(12)
=z^2+12z−12z−144
=z^2−144
Given :
Tickets cost $3 for students and $5 for adults.
A total of 125 people attended the concert for a total ticket sales of $475.
To Find :
The number of students and adults that attended the concert.
Solution :
Let, number of students and adults that attended the concert is x and y.
Mathematical equation of given conditions :
x + y = 125 ....1)
3x + 5y = 425 ....2)
Putting value of x from 1 to equation 2 is :
3( 125 - y ) + 5y = 425
375 - 3y + 5y = 425
2y = 50
y = 25
x = 125 - 25
x = 100
Therefore, number of students and adults that attended the concert is 100 ans 25 respectively.
Hence, this is the required solution.
Answer: x=4.5
Step-by-step explanation:
The question is in standard form as y = ax^2 + bx + c.
And as such, the axis of symmetry is given as x = - b / 2a
From the question above, a =1 and b = - 9
Therefore axis of symmetry is;
x = - (-9) / 2(1) which gives;
x = 9/2 or x=4.5