My complete work :
Given :
Sum of all angles in a triangle = 180°
Which means :
[tex] = \tt61 + 15x - 1 = 180[/tex]
[tex] =\tt 61 - 1 + 15x = 180[/tex]
[tex] =\tt 60 + 15x = 180[/tex]
[tex] = \tt15x = 180 - 60[/tex]
[tex] =\tt 15x = 120[/tex]
[tex] = \tt \: x = \frac{120}{15} [/tex]
[tex] =\tt x = 18[/tex]
- Thus, the value of x = 18
Measure of angle 15x-1 :
[tex] = \tt15 \times 8 - 1[/tex]
[tex] =\tt120 - 1[/tex]
[tex] =\tt 119[/tex]
Thus, the measure of angle 15x-1 = 119°
Let us place 8 in the place of x to see if we have found out the correct measure of the angles :
[tex] = \tt40 + 21 + 119 = 180[/tex]
[tex] = \tt61 + 119 = 180[/tex]
[tex] =\tt 180 = 180[/tex]
Since the measures of all the angle sum up to form 180°, we can conclude that we have found out the correct measure of each of the angles.
Therefore, the value of x = 8
My answer :
[tex]\boxed{\color{plum}\bold{x = 8}}[/tex]
