Question

if two supplementary angles differ from one another by 70 ° , determine the measure of both the supplementary angles

Answer 1

Let one of the angles be x.
Another angle = (180-x) [ because another supplementary angle will be the difference this angle and 180 degree]

According to question,

x-(180-x)= 70
x-180+x=70. [ removing bracket, signs changed]
2x=70+180
x= 150/2
x= 75 degree. [150/2= 75 degree]
Another angle= (180-75)
= 105 degree
one angle = 75 degree
Another angle= 105 degree

Answer 2

x-y=70
x+y=180
2x=250
x=125
y=55