Respuesta :

rcghda

Answer:

50 of D and 10 of C

Step-by-step explanation:

First of all, put this data into 2 equations.

You sold 60 items, so C+D=60

C is $5 so we can represent it by 5C

D is $7 so we can represent it by 7D

You made $400 total from C and D, so 5C+7D=400

We can use simultaneous equations to solve this.

To eliminate one of these variables, we'll multiply the first one by 5 to make it 5C like the other.

5(C+D=60)     (make sure you multiply both sides.)

so 5C+5D=300

5C+7D=400

Now we solve it:

5C-5C+7D-5D=400-300

7D-5D=100

2D=100

D=50

Now we can substitute this with one of the equations to find C

C+50=60

C=60-50

C=10

so, (10x5)+(50x7)=400