Question

find the value of polynomial for each
$5 - 4x ^{2} + 3$
at i) x=5 ii)x= -3​

Answer 1

Solution

i. When x = 5

This means that wherever there is x we have to put 5 in that place

So,

$5 - {4x}^{2} + 3$

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

$= > 5 - 4 \times 25 + 3$

$= > 5 - 100 + 3$

$= > 8- 100$

$\huge{\boxed{= - 92}}$

ii. When x = - 3

This means that wherever there is x we have to put - 3 in that place.

So,

$5 - 4 {x}^{2} + 3$

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

$= > 5 - 4 \times 9 + 3$

$= > 5 - 36 + 3$

$= > 8 - 36$

$\huge{\boxed{= -28}}$