What is -7/ 12 plus 7/10 in simplest form

The transitive property of equality states that: o if a = b, then bra o if a = b, then ac = bc o if a = b and b= c, then a = if a = b and c= c, then a + b = b + c

The longer leg of a 30° 60° 90° triangle is 16 times square root of three how long is a shorter leg

Im literally having a mental breakdown