James is making painted boxes. He wants the surface area of his boxes to be larger than 144cm² in order for his design to fit. He also wants the ratio of the side's lengths to be 1:2:2. Fin an inequality that the shortest length must satisfy.

Respuesta :

Answer:

The inequality that the shortest length must satisfy is [tex]\( x > 3 \).[/tex] This means that the shortest side length must be greater than 3 cm for the surface area to be larger than 144 cm².

Step-by-step explanation:

Let's denote the lengths of the sides of the box as [tex]\( x \), \( 2x \), and \( 2x \) (since the ratio of the side lengths is 1:2:2).[/tex]

The surface area of the box can be calculated using the formula for the surface area of a rectangular box:

[tex]\[ \text{Surface Area} = 2lw + 2lh + 2wh \][/tex]

Given that the lengths of the sides are[tex]\( x \), \( 2x \), and \( 2x \)[/tex], we can substitute these values into the formula:

[tex]\[ \text{Surface Area} = 2(x)(2x) + 2(x)(2x) + 2(2x)(2x) \][/tex]

[tex]\[ \text{Surface Area} = 4x^2 + 4x^2 + 8x^2 \][/tex]

[tex]\[ \text{Surface Area} = 16x^2 \][/tex]

Now, we want the surface area to be larger than 144 cm²:

[tex]\[ 16x^2 > 144 \][/tex]

Divide both sides by 16:

[tex]\[ x^2 > \frac{144}{16} \][/tex]

[tex]\[ x^2 > 9 \][/tex]

Take the square root of both sides (note that [tex]\( x \)[/tex] must be positive):

[tex]\[ x > 3 \][/tex]

So, the inequality that the shortest length must satisfy is [tex]\( x > 3 \).[/tex] This means that the shortest side length must be greater than 3 cm for the surface area to be larger than 144 cm².