Carrancoalonso
contestada

The coast of one orange r, and three apples, a, is $7. Three oranges and three apples cost $9. What is the cost of one apple ? What is the cost of one orange ?

Respuesta :

crisforp
o + 3a   = 7 ;
3o + 3a = 9 ;
____________(-)
-2o       = -2;
o = $1;
3a = 6;
a = $2.
jasongreen1
1r + 3a = 7
3r + 3a = 9

Then you can add or subtract these together . In this case we will subtract so we can remove the apples and get an answer for the oranges

(1r + 3a)-(3r+3a) = 7-9
-2r = -2
R = 1

So now by adding the value of r into one of the equations we can find the value for a

1r+3a=7
1+3a=7
3a = 6
A= 6/3
A= 2