Respuesta :
Step-by-step explanation:
let number of brand new busses = x
let number of secound hand busses = y
from first condition
x + y = 20
x = 20 - y
cost of brand new busses = 8000x
cost of scount hand bus = 3500y
8000x + 3500y = 160000
8000( 20 - y ) + 3500y = 106000
160000 - 8000y + 3500y = 106000
-4500y = -54000
y = 12
x = 20 - y
x = 8
Answer:
New minibuses = 8 ; second hand minibuses = 12 ; cost of second hand minibuses= $42,000
Step-by-step explanation:
we can indicaté the brand new ones with x and the second hand ones with y
with the information given we can build a system of two equations
x + y = 20
8000x + 3500y = 106000
we can solve it for example with the substitution method
x = -y+ 20
we can divide each member of the second expression for 100
80x + 35y= 1060
than for 5
16x + 7y = 212
now we can substitute x in the expression
16(-y+20) + 7y = 212
we can now solve the equation
-16y + 320 + 7y = 212
-9y = -108
y = 12 (the number of the second hand mini buses)
we can now substitute y in the first equation and solve it
x = -12 + 20
x = 8 (the number of the new minibuses)
For find the total cost of the second hand minibuses we have just to multiply
3500 x 12 = $42.000