Question

the isosceles triangle has a perimeter of 7.5 m. which equation can be used to find the value of x if the shortest side, y, measures 2.1 m? 2x - 2.1 = 7.5 4.2 + y = 7.5 y - 4.2 = 7.5 2.1 + 2x = 7.5

Explanation:

Step1: Recall the perimeter formula for an isosceles triangle

The perimeter \( P\) of a triangle is \(P=a + b+ c\). For an isosceles triangle with two equal sides \(x\) and side \(y\), \(P = 2x + y\).

Step2: Substitute the known values of \(P\) and \(y\) into the formula

Given \(P = 7.5\) and \(y=2.1\), we substitute into \(2x + y=P\). So, \(2x+2.1 = 7.5\).

Answer:

\(2x + 2.1=7.5\) (the first option)