Solve for X: Triangle with Sides 2X, 3X, and 3.5X Having 17cm Perimeter

The solution involves calculating the unknown $X$ using the perimeter provided for the triangle ABC:

• The equation representing the perimeter of triangle ABC is:
  $2X + 3X + 3.5X = 17$.
• Combine like terms:
  $8.5X = 17$.
• To find $X$, divide both sides by 8.5:
  $X = \frac{17}{8.5}$.
• Calculate the division:
  $X = 2$.
• Verify by checking the perimeter with $X = 2$:
  $2 \times 2 + 3 \times 2 + 3.5 \times 2 = 4 + 6 + 7 = 17$, which matches the given perimeter.

Thus, the value of $X$ is $2$.