How do you solve this system by elimination?

-3x+4y=12
2x+y=-8

i dont know how to solve it.

Brian, chris, and damien took a math test that had 20 questions. the number of questions brian got right is 14 more than the number of questions chris got right. damien correctly answered 2 less than the number of questions chris answered correctly. if brian and damien have the same score, which statement is true?

If the measure of angle 1 is 110 degrees and the measure of angle 3 is (2 x+10 degree), what is the value of x?

The radius of the circle below intersects the unit circle at (3/5,4/5). what is the approximate value of theta? 0.6 radians 1.0 radians 36.9 degrees 53.1 degrees