Answer:
Greatest solution of x = 4
Step-by-step explanation:
x² + 8x - 30 = 18
subtract 18 from both sides
x² + 8 x - 30 - 18 = 18 - 18
x ² + 8 x - 48 = 0
split 8x in middle form
x² + ( 12 x - 4 x ) - 48 = 0
factor out x from the first pair
x ( x + 12 ) - ( 4 x- 48 ) = 0
factor out 4 from the second pair
x ( x + 12) - 4 ( x + 12 ) = 0
x + 12 is common factor
x ( x + 12) - 4 ( x + 12 ) = 0
Group common factor
(x - 4) ( x + 12 ) = 0
When the product of factors equal 0, at least one factor is 0.
x - 4 = 0
x = 4
similarly,
x + 12 = 0
x = - 12
Greatest solution of x = 4
