Answer:
Vertical angle are those angles which are opposite to each other and are equal.
As per the statement:
A pair of vertical angles have measures (2z+43)° and (−10z+25)°
By definition we have;
\(2z+43 = -10z+25\)
Add 10z to both sides we get;
\(12z+43 = 25\)
Subtract 43 from both sides we get;
\(12z+43-43= 25-43\)
Simplify:
\(12z= -18\)
Divide both sides by 12 we get;
z = -1.5
therefore, the value of z is -1.5
