In which of the following expressions does the "x" term have a coefficient of -1?
a) 2x2+6x−1
b) 3x2−x−4
c) −2x2+x+7
d) −x2+3x+1
d) −x^2+3x+1
To determine which expression has a coefficient of -1 for the "x" term, we need to look at the term that includes "x" and check its coefficient.
a) 2x^2 + 6x - 1: The coefficient of the "x" term is 6, not -1.
b) 3x^2 - x - 4: The coefficient of the "x" term is -1. This expression has the "x" term with a coefficient of -1.
c) -2x^2 + x + 7: The coefficient of the "x" term is 1, not -1.
d) -x^2 + 3x + 1: The coefficient of the "x" term is 3, not -1.
Therefore, the expression with the "x" term having a coefficient of -1 is b) 3x^2 - x - 4.
To find the coefficient of the "x" term in each expression, we look for the number directly in front of the "x". In other words, we need to identify the number that multiplies the "x".
a) The coefficient of the "x" term in 2x^2 + 6x - 1 is 6. It is not -1.
b) The coefficient of the "x" term in 3x^2 - x - 4 is -1. It matches the requirement.
c) The coefficient of the "x" term in -2x^2 + x + 7 is 1. It is not -1.
d) The coefficient of the "x" term in -x^2 + 3x + 1 is 3. It is not -1.
So, the correct answer is b) 3x^2 - x - 4.