Answer:
Step-by-step explanation:
Let denotes number of pencils, markers, erasers respectively.
For Andrea:
For Justin:
For Virginia:
On subtracting equations (i) and (ii), we get
Put in equation (i)
Put in equation (iii)
Multiply equation (iv) by 5 and equation (v) by 6 and then subtract both the equations.
Put in equation
Put in equation (i)
Answer:
b. 4x^2 + 3x - 6
Step-by-step explanation:
The values of f(x) for the extremes of x are more positive than the value of f(x) for the middle x, so we know the parabola opens upward. That eliminates choice D.
It is probably easiest to evaluate the other expressions to see which one matches the given f(x) values. For the purpose, it is usually easier to use the Horner form of the equation.
a. f(-2) = (3(-2) +4)(-2) -6 = -2(-2) -6 = -2 ≠ 4
b. f(-2) = (4(-2) +3)(-2) -6 = -5(-2) -6 = 4 . . . . matches the given data point
c. Because (b) matches, we know this one will not.
The appropriate choice is B.
