Answer :
We know that the triangle is isosceles, which means it has two equal sides. Let these equal sides be $x$ and the third side (the shortest) be $y$. We are given:
- Perimeter: $$7.5 \text{ m}$$
- Shortest side: $$y = 2.1 \text{ m}$$
Since the perimeter is the sum of all three sides, we can write the equation:
$$
2x + y = 7.5
$$
Substituting $$y = 2.1$$ into the equation, we obtain:
$$
2x + 2.1 = 7.5
$$
Thus, the correct equation to find the value of $$x$$ is:
$$
2.1 + 2x = 7.5.
$$
To solve for $$x$$, we subtract $$2.1$$ from both sides:
$$
2x = 7.5 - 2.1 = 5.4.
$$
Now, divide by 2:
$$
x = \frac{5.4}{2} = 2.7.
$$
So, the value of $$x$$ is $$2.7 \text{ m}$$.
Therefore, the equation that can be used to find the value of $$x$$ is:
$$
\boxed{2.1 + 2x = 7.5.}
$$
- Perimeter: $$7.5 \text{ m}$$
- Shortest side: $$y = 2.1 \text{ m}$$
Since the perimeter is the sum of all three sides, we can write the equation:
$$
2x + y = 7.5
$$
Substituting $$y = 2.1$$ into the equation, we obtain:
$$
2x + 2.1 = 7.5
$$
Thus, the correct equation to find the value of $$x$$ is:
$$
2.1 + 2x = 7.5.
$$
To solve for $$x$$, we subtract $$2.1$$ from both sides:
$$
2x = 7.5 - 2.1 = 5.4.
$$
Now, divide by 2:
$$
x = \frac{5.4}{2} = 2.7.
$$
So, the value of $$x$$ is $$2.7 \text{ m}$$.
Therefore, the equation that can be used to find the value of $$x$$ is:
$$
\boxed{2.1 + 2x = 7.5.}
$$