Consider the equation y=2x2+9x+1.
When x=−1, what is the value of y?
This question is a 'enter correct answer'. It doesn't give me any options. But, I did the math three times already, shouldn't
Y=-10?
well, just plug in -1 for each x:
y = 2(-1)^2 + 9(-1) + 1
= 2-9+1
= -7
(-1)^2 = (-1)(-1) = +1
Online "^" is used to indicate an exponent, e.g., x^2 = x squared.
A negative times a negative = a positive.
y = 2x^2 + 9x + 1 = 2(1) + (-9) + 1 = ?
--Steve-
--PsyDAG-okay, so 2(1) + (-9) + 1 = -6, right?
correct. Sorry about by typo.
that's fine, I appreciate the help. Thank you guys!
To find the value of y when x = -1 in the equation y = 2x^2 + 9x + 1, you can substitute -1 into the equation for x and then solve for y.
Substituting x = -1 into the equation, we have:
y = 2(-1)^2 + 9(-1) + 1
Simplifying the terms, we get:
y = 2(1) - 9 + 1
y = 2 - 9 + 1
y = -6
Therefore, when x = -1, the value of y is -6, not -10.