1. The total interest earned will be .07x + .12(47000 + 4x) = 49640. Simplify and solve for x.

2. Write an equation for the total amount of minoxdil. .01(80) + .09(x) = .07(80 + x).

3. Write an equation for the total amount of antifreeze. .3(100) + .5x = .4(100 + x).