Question

Use gaussian elimination to solveThe buries pay their babysitter $5 per hour before 11 p.m. and $7.50 after 11p.m. One evening they went out for 5 hours and paid the sitter $35.00. What time did they come home?

Answer 1

Let m represents the number of hours the buries spent before 11p.m

Let n represent the number of hours the buries spent after 11p.m

m + n = 5 -----------equation (1)

5m + 7.5n = 35 -------equation (2)

Using Gaussian elimination method to solve the simultaneous equations, we have

`\begin{bmatrix}{1} & {1} & {5} \\ {5} & {7.5} & {35} \\ {} & {} & \end{bmatrix}-\begin{bmatrix}{\square} & {\square} & {\square} \\ {\square} & {\square} & {\square} \\ {\square} & {\square} & {\square}\end{bmatrix}`

The value of m = 1, while n = 4

This implies the buries spent 4 hours after 11 p.m

That means they come home by 3 a.m