Final answer:
By setting up an equation to represent the perimeter of the triangle as the sum of its three sides and solving for x, we find the value of x to be 7.
Step-by-step explanation:
The student has given the sides of a triangle as x, x+3, and 2x−1, and states that the perimeter is 30. To find the value of x, we can set up an equation by adding these sides and setting them equal to the perimeter:
x + (x+3) + (2x-1) = 30
Combining like terms, we get:
4x + 2 = 30
Subtracting 2 from both sides, we obtain:
4x = 28
Dividing both sides by 4 gives us:
x = 7
Thus, the value of x is 7 for the sides of the given triangle to add up to a perimeter of 30.