At what angle θ1 to the normal would the first dark ring be observed?

Steve is scuba diving near his home in maui. at one point he is 100 feet below the surface. represent this number with a negative number. if he descends another 5 feet, what negative number will represents his.

Which linear equations have an infinite number of solutions? check all that apply.  (x  –  3/7)  =  2/7(3/2x  –  9/14)8(x  +  2)  =  5x  –  1412.3x  –  18  =  3(–6  +  4.1x)(6x  +  10)  =  7(x  –  2)4.2x  –  3.5  =  2.1 (5x  +  8)

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"