Question

The square of a number decreased by 4 times the number equals 21. Find the number.

Answer 1

Answer: 7

Step-by-step explanation:

x^2-4x=21

x^2-4x-21=0

(x+3)(x-7)=0

x=-3

x=7

*** if you need to find the positive # only, the ANSWER is 7****