Solve 3(2y - 3/10) ≤ 19.4 - y two different ways.

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m

Solve each quadratic equation by factoring and using the zero product property. n^2 - 49 = 0