Solution:
The perimeter of the triangle shown is represented by the expression 10x - 1
The lengths of two sides are given: 3x + 1 and 5x - 2
We have to find the length of third side
We know that,
perimeter of the triangle = sum of length of all three sides
10x - 1 = 3x + 1 + 5x - 2 + third side
10x - 1 = 8x - 1 + third side
third side = 10x - 1 - 8x + 1
third side =2x
2x has variable x and its power is 1
Linear expression is an algebraic expression where the power of variable is equals to 1
Thus linear expression represents the missing length
