Question

last week mrs. kitts sold 6 more than 3 times that the sold this week. she sold over 110 cds over the 2 weeks. which systems of equations can be used to find the number of cds she sold last week and the number of cds she sold this week?

Answer 1

The system of equations are:

`y=3x+6\\x+y=110`

CDs sold this week is 26 and that of last week is 84.

Explanation:

Let the number of CDs sold this week be
`x` and last week be
`y`

Given:

CDs sold last week = 6 more than 3 times she sold this week

∴
`y = 3x+6`------------- 1

Also, total number of CDs sold are 110.

∴
`x+y=110` ------------ 2

Therefore, the above two equations are systems of equations that can be used to find the number of CDs she sold last week and the number of CDs she sold this week.

Now, in order to solve, we plug in the value of
`y` from equation (1) in equation (2). This gives,

`x+(3x+6)=110\\x+3x+6=110\\4x+6=110\\4x=110-6\\4x=104\\x=26`

Now,
`y=3x+6=3(26)+6=78+6=84`

Therefore, the number of CDs sold this week is 26 and last week is 84.