Question

10 times a number subtracted from the square of that number gives 144.
A. Write down a second degree equation by taking the number as x.
B. What is the number?

Answer 1

Step-by-step explanation:

let the number be x

$1 {x}^{2} - 10x = 144 \\ {x}^{2} - 10x - 144 = 0 \\ \: is \: second \: degree \: equation \\ {x}^{2} - 10x + 25 = 144 + 25 \\ {(x - 5)}^{2} = {13}^{2} \\ case1 \\ x - 5 = 13 \\ x = 18 \\ case \: 2 \\ x - 5 = - 13 \\ \times = - 13 + 5 \\ x = - 8$