2. Find the point of intersection of the lines 2x + y = 4 and 3x - y = 1. Graph the pair of lines.
3. A manufacturer produces items at a daily cost of $1.50 per item and sells them for $2.50 per item. The daily operational overhead is $500. What is the break-even point?
4. Suppose the sales of a company are given by
S(x) = $300x + $3,000 where x is measured in years and x = 0
corresponds to the year 2003.
Find the predicted sales in the year 2006 assuming the trend continues.
5. Write the augmented matrix of the system: x - 2y + z = 3
2x - y = 4
3y + z = 6
6. Perform the row operation R1 + (-2) R2  R1 on the matrix .
7. y = z x + y = 5.
Determine whether this system has a unique solution, no solution, or infinitely
many solutions. If a solution exists, write it down.
EC. a) Find the inverse of: .
b) Use it to solve the following system of equations:
- x1 - x2 - x3 = 1
4 x1 + 5x2 = - 2
x2 - 3 x3 = 3.
1. First we need to write the equation in slope-intercept form:
3x-y = 5
The slope is the coefficient of x, so slope is 3
We need to solve these two equations. We can do this using the substitution method:
Solve one equation for y:
Substitute this value for y in the other equation
3x - (4-2x)=1
Substitute this value for x in the first equation
Check using the second equation
Graph is on Excel file
3. Cost is 500 + 1.50x
Income is 2.50x
Break-even is where ...
This shows how to find intersections, slope, and break-even points.