Solve the equation

x^2 + 4x - 7

By completing the square

give answer correct to two decimal places.

(p. s the answer is not - 5.32 or 1.32)

x = 1.32, - 5.32

Step-by-step explanation:

x^2 + 4x - 7

Set equal to zero

x^2 + 4x - 7 = 0

Add 7 to each side

x^2 + 4x = 7

Take the coefficient of x and divide by 2

4/2

Square it

2^2 = 4

Add to each side

x^2+4x+4 = 7+4

(x+2) ^2 = 11

Take the square root of each side

x+2 = ±sqrt (11)

Subtract 2 from each side

x = - 2 ±sqrt (11)

x=1.31662

x=-5.31662

To 2 decimal places

x = 1.32, - 5.32