{x}^(2) - 4x = 21 what are the x intercepts? ​

Question

`{x}^(2) - 4x = 21`
what are the x intercepts?
​

Answer 1

x² - 4x = 21

x² - 4x - 21 = 0

x² - 7x + 3x - 21 = 0

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

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

x + 3 = 0 and x - 7 = 0

x = -3 and x = 7