math problem?

Question

The cost of an Aardvark personal computer is $40 less than twice the cost of an Afghan computer, while and armadillo computer costs $70 more than an Afghan..
If an order of two Afghans, one Aardvark, and three armadillos totals $ 6820, what is the cost of each type of computer?

Please show ur work.Thank you.

Answer 1

a=afghan cost
b=aardvark cost
c=armadillos cost

EQUATION 1: 2a+1b+3c=6820
EQUATION 2: b=2a-4
EQUATION 3: c=a+70

substitute "b" and "c" with the above equations to get...

2a+(2a-40)+3(a+70)=6820
now simplify
4a-40+3a+210=6820
7a+170=6820
7a=6650
a=$950, an AFGHAN costs $950

now subsitute in "a" for the equations 2 and 3.
b=2a-40
b=2(950)-40
b=$1860, an Aardvark costs $1860

c=a+70
c=($950)+70
c=1020, an Armadillo costs $1020

Answer 2

Aardvark = x-40
Afghan = x
armadillo = x+70


2 Afghan = 2x
1 Aardvark = x-40
3 armadillo = 3(x+70) = 3x+210

Thus,
Total Cost = 2x + x-40 + 3x+210

But,
Total Cost = 6820

2x + x-40 + 3x+210 = 6820
6x + 170 = 6820
x = $1108.33

Thus,

Aardvark = 1108.33-40 = 1068.33
Afghan = 1108.33
armadillo = 1108.33+70 = 1178.33

Answer 3

x = cost of Afghan computer
2x-40 = cost of Aardvark computer
x+70 = cost of Armadillo computer
So 2x + 2x-40 +3(x+70)=6820
7x = 6650
x = $950 = cost of Afghan
2x-40 = $1860 = cost of Aardvark
x+70= $1020 = cost of Armadillo

Answer 4

Let the cost of Aardvark pc be X, Afghan pc be Y and Armadillo pc be z.
Then:
X=2Y-40
Z=Y+70
2Y+X+3Z=6820
X=2Y-40.............2Y=X+40
Z=Y+70.....Z=(X+40)/2+70
X+40+X+1.5(X+40)+210=6820
3.5X=6510.........X=1860.............Y=950........Z=1020

Answer 5

aardvark = x
afghan = y
armadillo = z

x = 2y - 40
z = y + 70
2y + x + 3z = 6820

SUBSTITUTION (simultaneous equations)

2y + 2y - 40 + 3(y + 70) = 6820
4y - 40 + 3y + 210 = 6820
7y + 170 = 6820
7y = 6990
y = 998.57 (2 d.p.)

x = 2y - 40
x = 2(998.57) - 40
x = 1997.14 - 40
x = 1957.14

z = y + 70
z = 998.57 + 70
z = 1068.57

aardvark = 1957.14
afghan = 998.57
armadillo = 1068.57

Answer 6

i don't belive in doing homework for other people, but here is a good help on trying to solve it for youself. write down each name in a list and what you know about each of the computers. i've done lots of problems like that before. just take the time to tear apart the wording and figure it out. what's the point of homework if you aren't going to get anything out of it.