Question

The value of f(x)=5x-4x²+3 when x=-1, is:
1 point

Answer 1

$f(x) = 5x - 4 {x}^{2} + 3$

For $x=-1$, all we have to do is plug in "$-1$" for all values of "$x$".

And so we have,

$f( - 1) = 5 ( - 1) - 4( { - 1})^{2} + 3$

$= - 5 - 4( - 1 \times - 1) + 3$

$= - 5 - 4( + 1) + 3$

$= - 5 - 4 + 3$

$= - 9 + 3$

$= - 6$