13≥-x+7

can someone explain this to me? i dont understand how to do this

If angle 2=3x +1 and angle 3=2x +4what is angle 2

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

6x + 3y = -6 2x + y = -2 a. x = 0, y = -2 b. infinite solutions c. x = -1, y = 0 d. no solution