Question

Find the value of polynomial 8x² + 7x-5 when x = 4.​

Answer 1

Question:-

$8 {x}^{2} + 7x - 5$

Given:-

$x = 4$

To Find:-

The value of the equation

Solution:-

$8 {x}^{2} + 7x - 5 \\ 8 {(4)}^{2} + 7 \times 4 - 5 \\ 8 \times 16 + 28 - 5 \\ 128 + 28 - 5 \\ 128 + 23 \\ 151$

u'r done!!

Thnx✌️♥️~

Answer 2

Answer:

151

Step-by-step explanation:

Plugging in $x=4$ gives us:

$8x^{2} +7x-5=8\times4^{2} +7\times4-5$

Due to the order of operations (called BEDMAS, PEMDAS, BODMAS, etc. in different countries), we evaluate the exponent first since there are no grouping symbols saying otherwise: $4^2=16$.

$8x^2+7x-5=8\times16+7\times4-5$

The order of operations then suggests to multiply and divide from left to right: $8\times16=128$ and $7\times4=28$.

$8x^2+7x-5=128+28-5$

Finally, the order of operations tells us to add and subtract from left to right.

$8x^2+7x-5=156-5$

$8x^2+7x-5=151$ (This is the final answer!)

Let me know if you have any further questions. :)