Answer:
x = 6, x = 7
Explanation:
Given
x =
← square both sides
x² = 13x - 42 ← subtract 13x - 42 from both sides
x² - 13x + 42 = 0 ← in standard form
(x - 6)(x - 7) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 6 = 0 ⇒ x = 6
x - 7 = 0 ⇒ x = 7
As a check substitute these values into the right side of the equation and if equal to the left side then they are the solutions
x = 6 :
=
= 6 ← solution
x = 7 :
=
= 7 ← solution