The difference of a number and 4 is maximum of 33

Which equation and solution can be used to solve this problem? thirteen less than a number is sixteen. 13-n=16: add 13 to both sides. the answer is 29. n+13=16: subtract 13 from both sides. the answer is 3. n+16=13 subtract 13 from both sides. the answer is 3. n-13=16: add 13 to both sides. the answer is 29.

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Evaluate cos2θ for cosθ = square root of 3/2