Answer :
An isosceles triangle has two equal sides. Let each of these equal sides be of length [tex]$x$[/tex], and let the shortest side be [tex]$y$[/tex]. The perimeter of the triangle is the sum of all its sides, so we have
[tex]$$
y + 2x = 7.5.
$$[/tex]
We are given that [tex]$y = 2.1$[/tex] m. Substituting [tex]$y = 2.1$[/tex] into the equation gives
[tex]$$
2.1 + 2x = 7.5.
$$[/tex]
This is the equation that can be used to find the value of [tex]$x$[/tex].
To solve for [tex]$x$[/tex], subtract [tex]$2.1$[/tex] from both sides:
[tex]$$
2x = 7.5 - 2.1 = 5.4.
$$[/tex]
Then, divide both sides of the equation by [tex]$2$[/tex]:
[tex]$$
x = \frac{5.4}{2} = 2.7.
$$[/tex]
Thus, the correct choice is the equation
[tex]$$
2.1 + 2x = 7.5.
$$[/tex]
[tex]$$
y + 2x = 7.5.
$$[/tex]
We are given that [tex]$y = 2.1$[/tex] m. Substituting [tex]$y = 2.1$[/tex] into the equation gives
[tex]$$
2.1 + 2x = 7.5.
$$[/tex]
This is the equation that can be used to find the value of [tex]$x$[/tex].
To solve for [tex]$x$[/tex], subtract [tex]$2.1$[/tex] from both sides:
[tex]$$
2x = 7.5 - 2.1 = 5.4.
$$[/tex]
Then, divide both sides of the equation by [tex]$2$[/tex]:
[tex]$$
x = \frac{5.4}{2} = 2.7.
$$[/tex]
Thus, the correct choice is the equation
[tex]$$
2.1 + 2x = 7.5.
$$[/tex]
