How do you solve using the completing the square method #x ^2 + 13 x + 42 = 0#?
For a very detailed example of method see
I will let you solve the other bits!
The process applied introduces an error that is removed by adding the correction factor of
Add the correction factor of
Take the power to outside the brackets
Halve the coefficient of
The error comes from
Find x-intercepts by substituting 0 for y and solve in the normal way
y-intercept is the constant in the original equation = +42
I will let you solve for the x-intercepts