Question

5x^2 - x + 9 when x = -5

Answer 1

Answer: 139

Concept:

Here, we need to understand the idea of evaluation.

When encountering questions that gave you an expression with variables, then stated: "If x = a, y = b, z = c" (a, b, c are all constants), this means you should substitute the value given for each variable back to the expression.

Solve:

Given information

5x² - x + 9

x = -5

Substitute value into the expression

=5(-5)² - (-5) + 9

Simplify exponents

=5 (25) + 5 + 9

Simplify by multiplication

=125 + 5 +9

Simplify by addition

=
`\boxed {139}`

Hope this helps!! :)

Please let me know if you have any questions

Answer 2

139

Explanation:

If x=-5

then

5*-5^2-(-5)+9

5*25+5+9

139