College

The isosceles triangle has a perimeter of 7.5 m. Which equation can be used to find the value of [tex]x[/tex] if the shortest side, [tex]y[/tex], measures 2.1 m?

A. [tex]2x - 2.1 = 7.5[/tex]
B. [tex]4.2 + y = 7.5[/tex]
C. [tex]v - 4.2 = 7.5[/tex]
D. [tex]2.1 + 2x = 7.5[/tex]

Answer :

Let's solve this step-by-step.

Given:
- The perimeter of the isosceles triangle is [tex]\(7.5\)[/tex] meters.
- The shortest side ([tex]\(y\)[/tex]) measures [tex]\(2.1\)[/tex] meters.

In an isosceles triangle, two sides are equal in length, and one side is different. Let’s denote:
- [tex]\(x\)[/tex] as the length of the two equal sides.
- [tex]\(y\)[/tex] as the length of the shortest side.

The formula for the perimeter of the isosceles triangle is:
[tex]\[ \text{Perimeter} = x + x + y \][/tex]

Substitute the given values into the perimeter equation:
[tex]\[ 7.5 = x + x + 2.1 \][/tex]

Simplify the equation:
[tex]\[ 7.5 = 2x + 2.1 \][/tex]

Rewrite the equation to isolate [tex]\(2x\)[/tex]:
[tex]\[ 2x + 2.1 = 7.5 \][/tex]

This matches one of the given options:
[tex]\[ 2.1 + 2x = 7.5 \][/tex]

Therefore, the correct equation to find the value of [tex]\(x\)[/tex] is:
[tex]\[ 2.1 + 2x = 7.5 \][/tex]

This equation can be used to find the value of [tex]\(x\)[/tex].