Question

una ventana rectangular tiene l metros de ancho y h metros de altura, con un perímetro de 6 metros y un área de 2m² ¿cuál es la fórmula para calcular el ancho de la ventana?​

Answer 1

Answer:

The formula for calculating the width of the window is

$w=\frac{-(-3)(+/-)\sqrt{-3^{2}-4(1)(2)}} {2(1)}$

Step-by-step explanation:

The question in English is

A rectangular window is l meters wide and h meters high, with a perimeter of 6 meters and an area of 2m². What is the formula for calculating the width of the window?

we know that

The perimeter of the window is equal to

$P=2(l+w)$

we have

$P=6\ m$

so

$6=2(l+w)$

simplify

$3=(l+w)$

isolate the variable l

$l=3-w$ ----> equation A

The area of the window is equal to

$A=lw$

we have

$A=2\ m^2$

so

$2=lw$ ----> equation B

substitute equation A in equation B

$2=(3-w)w$

solve for w

$2=3w-w^2$

$w^2-3w+2=0$

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$w^2-3w+2=0$

so

$a=1\\b=-3\\c=2$

substitute in the formula

$w=\frac{-(-3)(+/-)\sqrt{-3^{2}-4(1)(2)}} {2(1)}$  --->  formula for calculating the width of the window

$w=\frac{3(+/-)\sqrt{1}} {2}$

$w=\frac{3(+/-)1} {2}$

$w=\frac{3(+)1} {2}=2\ m$

$w=\frac{3(-)1} {2}=1\ m$