# Linear equations

1. Solve the inequality. Write the solution in interval notation and graph the set on the number line. -2(x - 4) 3x + 1 - 5x

2. Solve the following problem by writing an equation and then solving the equation: You invest $7,200 in two accounts paying 8% and 10% annual interest respectively. At the end of the year, the accounts earn the same interest. How much was invested at each rate?

3. Solve the following problem by writing an equation and then solving the equation: How many ounces of 50% alcohol solution must be mixed with 80 ounces of 20% alcohol to make a 40% alcohol solution?

4. Write the equation of the line that contains the point (-2, 3) and is perpendicular to y = 2x + 7. Write the equation in slope-intercept form.

5. Solve the system of linear equations by the substitution method: 4x + 3y = 0;

2x - y = 0.

6. Solve the system of linear equations by the addition method: (SEE ATTACHMENT)

https://brainmass.com/math/linear-algebra/linear-equations-31392

#### Solution Summary

This shows how to solve and write equations, find the equation of a line, and solve mixture problems.