<PRE><B>Question 619621</B>
Completing the Square:

x^2 + 3x = 28

The x term is 3x. Take half its coefficient (1.5). Square it (2.25) and add it to both sides.

Add 2.25 to each side of the equation.

x^2 + 3x + 2.25 = 28 + 2.25

Combine like terms:

28 + 2.25 = 30.25

Factor a perfect square on the left side:

(x + 1.5)(x + 1.5) = 30.25

Calculate the square root of the right side = 5.5

The square root of 30.25 = 5.5

Break this problem into two subproblems by setting:

(x + 1.5) equal to 5.5 and -5.5

Subproblem 1

x + 1.5 = 5.5

Subtract 1.5 from each side of the equation.

x + 1.5 - 1.5 = 5.5 - 1.5

Combine like terms:

1.5 - 1.5 = 0

5.5 - 1.5 = 4

x = 4

Subproblem 2

x + 1.5 = -5.5

Subtract 1.5 from each side of the equation.

x + 1.5 - 1.5 = -5.5 - 1.5

Combine like terms:

1.5 - 1.5 = 0

-5.5 - 1.5 = -7

x = -7

Solution:

x = 4, -7</PRE>