Question

2. Find the value of the polynomial 7x-3x2 +5 at x=-2.
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Answer 1

Given: The equation is$7x-3x^{2} +5$ and$x=-2$.

We have to find the above equation.

As we know that the value of $x$is given that is$x=-2$.

So by putting this value in the above equation, we are solving the above equation.

We are solving in the following way:

We have,

$7x-3x^{2} +5$ and$x=-2$

$=>7\times-2-3\times -2^{2} +5\\=>-14-3\times4+5\\=>-14-12+5\\=>-21$

Hence, the solution of the above equation is$-21$.

Answer 2

• We have to evaluate the above expression by using the given data.

              Given data:- $7x-3x^{2} +5.$

              To find:- Value of above expression.

              Solution:-

• To solve the above equation we will follow the BODMAS rule.

• BODMAS is an order of mathematic operations.

• BODMAS rule is to be followed while solving expressions in mathematics. It stands for,

               B= bracket

               O= order of power or rules

               D= division

               M= multiplication

               A= addition

               S= subtraction

       Now put the value x=-2 and  in the given equation we get,

             $7x-3x^{2} +5\\=7(-2)-3(-2)^{2} +5\\=(-14)-3(4)+5\\=(-14)-12+5\\=-21.$

        Hence we will get the value $7x-3x^{2} +5=-21.$