A ticket to a concert costs either $12 or $15. A total of 300 tickets are sold, and the total money collected is $4140 . The number of $12 tickets sold are?

Step-by-step explanation:

system of equations… so, in the first one, let x =amount of ticket A, let y = amount of ticket B.

So, x + y = 300 tickets

In equation two, we know $12 per ticket A, and $15 per ticket B, but we don’t know the amount of tickets.

So, $12x + $15y = $4,140.

So we can solve this using elimination, substitution, graphing it etc. etc.

I will use substitution, as I prefer that when I have one equation that is x +/- y =

so i prefer multiplying by 15, so I am going to solve for y.

x + y = 300

-x ……. -x

y = -x +300

No substitute the y value into the second equation…

$12x +$15(-x + 300) =$4,140.

so we distribute the 15

12x -15x + 4500 = 4140

combine like terms:

-3x +4500 = 4140

subtract 4500 from both sides

-3x = -360

divide both sides by -3

x = 120. So we know that there were 120 of tickets A bought

so we go back to our system and solve

x + y = 300, but use our newly acquired x value.

120 + y = 300

y = 180

So, 120 of ticket A, 180 of ticket B, and we could plug it in and get the same answer….. just for fun

12x + 15y = 4140

12 (120) + 15 (180)

1440 + 2700 = 4140.

24

step-by-step explanation:

the graph shows 30% of students walk. 80 students were questioned, so the number that said they walk is

30% × 80 = 0.30 × 80 = 24

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.