Answer:
x = - 2 ±
Step-by-step explanation:
To solve the equation using the method of completing the square.
Given
x² + 4x - 7 = 0 ( add 7 to both sides )
x² + 4x = 7
add ( half the coefficient of the x- term )² to both sides
x² + 2(2) x + 4 = 7 + 4
(x + 2)² = 11 ( take the square root of both sides )
x + 2 = ± ( subtract 2 from both sides )
x = - 2 ± ← exact solution
Answer: 70, 420, 170
Step-by-step explanation:
x+6x+x+100 = 660
8x+100=660
8x=660-100
x=560/8=70
Hi!
She would have to sell 8.
Because 125/7 = 17.86 and she can't sell 86/100 of a book, she has to sell 8.
Hope this helps! :)