Which three steps are correct when solving this quadratic equation by completing the square? x2 + 8x + 15 = 0
A)
x4 + 8x = -15
B)
x2 + 8x + 16 - 1
(x + 4)2 = 16
D)
(x + 4)2 = 1
E
x = -3 or x = 5

E

Step-by-step explanation:

transferring the constant

making the coefficient of x^2 to be 1

then add the square of half the coefficient of x

take the square root of both sides

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form