Answer :
The concept of supplementary angles is :
Sum of supplementary angles =180 degrees
Now let us say one of the supplementary angle measures x degrees.
finding expression for second angle,
half the measure of x is 0.5x
30 degrees less means subtracting 30 so we have 0.5x-30
now the two angles are x and 0.5x-30
Adding the two will be equal to 180 , so forming an equation,
[tex] x+0.5x-30 =180 [/tex]
[tex] 1.5x-30 =180 [/tex]
adding 30 on the right side,
[tex] 1.5x- =180+30 [/tex]
[tex] 1.5x- =210 [/tex]
dividing both sides by 1.5
x=210/1.5 = 140
So first angle is 140
our angle is 0.5x-30 which is 40 degrees
Answer is 40 degrees
supplementary angles add up to = 180
so,
x + y =180
but also, we are given that one of the angles is 30 less than half of the second which can also be written as
x = .5y - 30
we are looking for the value of x, so we can solve the first equation for y and then place it into the second equation
y = 180 - x
x = .5(180-x) -30
now we can solve for x
x = 90 - .5x -30
1.5x = 90 - 30
1.5x = 60
x = 40
so your answer should be
B) 40
hope this helps!