40 tickets were sold for a concert, some at 75 cents and the rest at $1.25. if the total raiwed was $42, how many had the cheaper ticket​

16 had the cheaper ticket

Step-by-step explanation:

Let the number of 75cents tickets be x

Let the number of $1.25 tickets be y

Since the total tickets is 40, hence;

x+y =40 1

Also if some are sold at 75 cents and the rest at $1.25 with total of $42 earned, then;

0.75x+1.25y = 42... 2

From 1

x = 40-y

Substitute into 2;

0.75(40-y)+1.25y = 42

30-0.75y+1.25y = 42

30+0.5y = 42

0.5y =42-30

0.5y = 12

y = 12/0.5

y = 24

Since x = 40-y

x = 40-24

x = 16

The number of cheaper ticket are 16

6hryt%4578855

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!