Question

ƒ(x) = x2 + 2x − 15 to find the solution when ƒ(x) = 0.

Answer 1

Answer:

f = 2 + -15x-1 + x

Step-by-step explanation:

Simplifying

f(x) = x2 + 2x + -15

Multiply f (x)

fx = x2 + 2x + -15

Reorder the terms:

fx = -15 + 2x + x2

Solving

fx = -15 + 2x + x2

Solving for variable 'f'.

Move all terms containing f to the left, all other terms to the right.

Divide each side by 'x'.

f = -15x-1 + 2 + x

Simplifying

f = -15x-1 + 2 + x

Reorder the terms:

f = 2 + -15x-1 + x

Answer 2

Answer:

$x = 3, -5$

Step-by-step explanation:

Step 1:  Set the equation to 0

$x^2+2x-15=0$

Step 2:  Factor

$x^2+2x-15=0$

$x^2-5x+3x-15=0$

$(x-3)(x+5)=0$

Step 3:  Solve for x

$x - 3 +3=0 +3$

$x = 3$

$x+5-5=0-5$

$x = -5$

Answer:  $x = 3, -5$