The length of the rectangle is 3 cm
From the question, we are to determine the value of the length of the rectangle
To find the length of the rectangle, we will determine the value of x in the given equation
The given equation is
[tex]x^{2} + 5x =24[/tex]
This can be written as
[tex]x^{2} +5x -24 =0[/tex]
Factorizing
[tex]x^{2} +8x - 3x -24 = 0 [/tex]
[tex]x(x+8) -3(x+8)=0[/tex]
[tex](x-3)(x+8)=0[/tex]
Then,
[tex]x-3 = 0[/tex] OR [tex]x + 8 = 0[/tex]
x = 3 OR x = -8
Since, the length of the rectangle cannot be negative, the value of x is 3.
Hence, the length of the rectangle is 3 cm.
Learn more on solving quadratic equations here: https://brainly.com/question/8649555