Kid's Math Homework.....Emergency!!?

let R = number of red cars sold and B = number of black cars sold

you know R + B = 44 = total number of cars sold (eq. a)

the total money made is given by

$105 = ($2/red car)R + ($3/black car)B

but you know from (eq. a) that R = 44 - B

$105 = ($2/car)(44 - B) + ($3/car)B

$105 = $88 - ($2/car)B + ($3/car)B

($1/car)B = $105 - $88 = $17/($1/car)

B = 17 cars

using (eq. a) again

R = 44 cars - B = 44 cars -17 cars = 27 cars

ok here goes...

let the red cars be R and the black cars be B

R+B=44

and

2R+3B=105

to solve for B, Subtract R...you have B=44-R

plug that into the equation for B... 2R+3(44-R)=105 and solve for R

2R+132-3R=105... did you see that I multipied 3&44? combine like terms

132-1R=105 and 105-132= -27 and -27divided by -1=27

so 27 red and 17 black

x = red cars

y = black cars

2x + 3y = 105

x + y = 44

Solve the second equation for x

x = 44 - y

Plug that into the first equation

2(44 - y) + 3y = 105

88 - 2y + 3y = 105

y = 17 subtracted 88 from both sides and combined the y's

Plug 17 into the second equation

x = 44-17

x = 27

set up a system of equations

2x+3y=105....(1)

x+y=44....(2)

x=red cars

y=black cars

solve that system of equation

Subtract x+y=44 from 2x+3y=105

x+2y=61

x=61-2y....(3)

Plug (3) into (2)

(61-2y)+y=44

61-y=44

-y=-17

y=17....(4)

we now know the number of black cars, but we are trying to find the number of red cars.

Simply plug (4) into (2) and this is what you get:

x+17=44

x=44-17

x=27

THE COMPANY SOLD 27 RED CARS

A fair number.