Solve the equations and inequalities below. Check your solutions, if possible. Homework Help ✎
Note the absolute value. When is an absolute value greater than or equal to −4?
all real numbers
Factor, and solve for x. Since this is an inequality, these are the boundary points.
(x − 4)(x + 5) < 0
The boundary points are 4 and −5.
Plot your boundary points on a number line. Test a point in each region to see which region(s) make the inequality true.
−5 < x < 4
This is a quadratic equation. Set it equal to 0. Then factor and use the Zero Product Property or use the Quadratic Formula to solve.
Fractions represent division. Multiply all terms by 9 to 'undo' the denominators.