Question

pablo folds a straw into a triangle with side lengths of $4x^2 - 3$ inches, $4x^2 - 2$ inches, and $4x^2 - 1$ inches. which expression can be used to find the perimeter of the triangle, and what is the perimeter when $x = 1.5$?
$12x^2$; 36 inches
$12x^2 - 6$; 30 inches
$12x^2$; 27 inches
$12x^2 - 6$; 21 inches

Explanation:

Step1: Sum all side lengths

$Perimeter = (4x^2 - 3) + (4x^2 - 2) + (4x^2 - 1)$

Step2: Combine like terms

$Perimeter = (4x^2+4x^2+4x^2) + (-3-2-1) = 12x^2 - 6$

Step3: Substitute $x=1.5$

First calculate $x^2$: $1.5^2 = 2.25$

Step4: Compute final perimeter

$Perimeter = 12\times2.25 - 6 = 27 - 6 = 21$

Answer:

12x² − 6; 21 inches