Question

The system of inequalities below describes the relationship between Cori's age C and Livy's age L. C + L ≥ 43 C - 4L ≤ 3 Livy could be 13 years old and Cori could be 35 years old.

Answer 1

Cori could be 35 years old.

Livy could be 8 years old

Explanation:

Given

`C + L \ge 43`

`C - 4L \ge 3`

Required

Possible values of C and L

Make C the subject in:
`C - 4L \ge 3`

`C \ge 3 + 4L`

Substitute for C in
`C + L \ge 43`

`3 + 4L + L \ge 43`

`3 + 5L \ge 43`

Collect like terms

`5L \ge 43-3`

`5L \ge 40`

Solve for L

`L \ge 8`

Solve for C

`C \ge 3 + 4L`

`C \ge 3 + 4 * 8`

`C \ge 35`