Answer:
x = 77
y = 72
z = 31
Step-by-step explanation:
The formula for the Perimeter of triangle XYZ = x + y + z
From the question:
x + y + z = 180
In the triangle, x is 5 greater than y,
x = y + 5
y is 21 less than three times z
y = 3z - 21
3z = y + 21
z = y + 21/3
Hence:using substitution
x + y + z = 180
y + 5 + y + y/3 + 21/3 = 180
2y + y/3 + 5 + 21/3 = 180
2y + y/3 = 180 - ( 5 + 21/3)
2y + y/3 = 180 - (5 + 7)
2y + y/3 = 180 - 12
2y + y/3 = 168
Multiply both sides by 3
2y × 3 + y/3 × 3 = 168 × 3
6y + y = 504
7y = 504
y = 504/7
y = 72
Solving for x
x = y + 5
x = 72 + 5
x = 77
Solving for z
z = (y + 21)/3
z = (72 + 21)/3
z = 93/3
z = 31
Therefore,
x = 77
y = 72
z = 31
