The sum of all angles at a point on a line is equal to 180°.
In the given figure, at line YXT, sum of all angles at X = 180
SOo, angle YXZ + angle ZXT = 180°
It is given that angle YXZ = 68°
SUbstitute the value and solve for ZXT
YXZ + ZXT = 180
68 + ZXT = 180
Angle ZXT = 180 - 68
Angle ZXT = 112°
Angle ZXV is the sum of angle ZXT and TXV
Angle ZXV = Angle ZXT + Angle TXV
Angle ZXV = 1