A college student invested part of a $25,000 inheritance at 7% interest and the rest at 6%. If his annual interest is $1,670 how much did he invest at 6%? If I told you the answer is $8,000, in your own words, using complete sentences, explain how you would solve the problem.
Solve each equation by factoring.
x^{2} + 8x + 15 = 0
Complete the square to make each binomial a perfect square triangle.
x^{2} - 12x
Use the quadratic formula to solve each equation.
6x^{2} + x - 2= 0
3x^{2 }+ 18x + 15= 0
Solve each problem.