Answer:
x = 8
Step-by-step explanation:
From the diagram above, since the triangle is an isosceles triangle and side AB is congruent to side CB, then angle A must be equal to angle B.
angle A = angle C
69° = 9y - 3
To get the value of y, we add 3 to both-side of the equation and then divide both-side of the equation by 9
69 + 3 = 9y -3 + 3
72 = 9y
Divide both-side of the equation by 9
72/9 = 9y/9
8 = y
y =8
But what we are looking for is x;
69° + (9y -3)° + (5x + 2)° = 180 ° ( sum of angle in a triangle)
To get the value of x, we will substitute y=8 in the equation above and then simplify
69 + 9(8) - 3 + 5x + 2 = 180
69 + 72 - 3 + 5x + 2 = 180
138 + 5x + 2 = 180
140 + 5x = 180
subtract both-side of the equation by 140
140 - 140 + 5x = 180 -140
5x = 40
Divide both-side of the equation by 5
5x/5 = 40/5
x = 8
Therefore the value of x is 8
