Question

If -2 is a root of the quadratic equation x²-5x+c find the value of c

Answer 1

Answer:

$\fbox{\begin{minipage}{4em}c = -14\end{minipage}}$

Step-by-step explanation:

Given:

A quadratic equation: $x^{2} - 5x + c = 0$, with $x =-2$ is a solution.

Solve for:

Value of c

Step 1: define the problem

If $x = -2$ is a solution of equation $f(x) = 0$, then $f(-2) = 0$

Step 2: Perform the calculation

Substitute $x = -2$ into original quadratic equation, we have:

$(-2)^{2} - 5(-2) + c = 0$

Perform the square and multiplication:

$4 + 10 + c = 0$

Transfer all of numbers to the right side, except c:

(notice for the change in sign of numbers)

$c = (-4) + (-10)$

Perform the sum on the right side to get c:

$c = -14$

Hope this helps!

:)

Answer 2

Answer:

Step-by-step explanation:

P(x)= x^2-5x+c=0

P (-2)= (-2)^2-5 (-2)+c=0

= 4+10+c=0

=14+c=0

C=(-14)