Answer:
The total number of CDs sold is 30, and the number of videos is 10.
Step-by-step explanation:
Consider A is the number of Videos sold.
Consider B is the number of CDs sold.
So,
A+ B= 40, B=40 -A
and
$6*A+ $4*B=$180
Replacing, B=40 -A in the second equation
$6*A+ $4*(40 -A)=$180
Distributive property
$6A+ $160 -$4A=$180
$6A -$4A=$180 - $160
$2A=$20
A=$20/$2=10
and B=40 -A, so B=40-10=30
That means, the number of Videos sold is 10
And the number of CDs sold is 30
Answer:
number of CD's = 30
number of videos = 10
Step-by-step explanation:
The combined number of CD's and Videos sold is 40.
Let the
number of CD sold = a
number of video sold = b
The CD is sold $4 per CD. The videos is sold $6 per video. The combined sales was $180.
Combined number of CD and video
a + b = 40.................(i)
Cost of the combined number of CD and video
4a + 6b = 180............(ii)
a + b = 40.................(i)
4a + 6b = 180............(ii)
a = 40 - b
insert a in equation(ii)
4(40 - b) + 6b = 180
160 - 4b + 6b = 180
160 + 2b = 180
2b = 180 - 160
2b = 20
divide both side by 2
b = 20/2
b = 10
insert b in equation(i)
a + b = 40.................(i)
a + 10 = 40
a = 40 - 10
a = 30
