Answer:
X=5
Step-by-step explanation:
(10x - 5)+(12x+30)+(7x+10)= 180 ... (sum of angles in a triangle)
=29x+35=180 ... (adding and subtracting only the like terms)
29x=180-35
29x = 145
(divide both sides by the coefficient of x "29")
Therefore x = 5
Then substitute the value of x (which is 5) into the expression of angles given.
Measurement of angle A:
10x-5
=10(5)-5
=50-5
=45°
Measurement of angle B:
12x+30
=12(5)+30
=60+30
90°
Measurement of angle C:
7x+10
=7(5)+10
=35+10
=45°
