The answer is -40 because if you get rid of the negative sign and add instead of subtract... you get 40 so its like adding in the opposite direction.
Answer: 17.68
Step-by-step explanation: just add the taxes, this is your final sale price.
For the equation of the line of the form y = mx + b, m is the slope of the line and b is the y-intercept which is the value of y when x is equal to zero. The slope is the rate of change of y per change in x. "y" would represent the dependent variable which is the weight of the baby while "x" represents the independent variable which is the number of months or the age of the baby in months. We calculate the slope as follows:
slope = (11 - 9) / ( 4 - 0) = 2/4 = 0.5
at x = 0, it is said that the weight of the baby is 9 lbs so the value of b would be 9.
The equation of the line would be y = 0.5x + 9
Remember that a quadratic equation is a parabola. The equation is of the type y = Ax^2 + Bx + C
A linear equation is a straight line. The equation is of the type y = MX + N
The soluction of that system is Ax^2 + Bx + C = MX + N
=> Ax^2 + (B-M)x + (C-N) = 0
That is a quadratic equation.
A quadratic equation may have 0, 1 or 2 real solutions. Those are all the possibilitis.
So you must select 0, 1 and 2.
You can also get to that conclusion if you draw a parabola and figure out now many point of it you can intersect with a straight line.
You will realize that depending of the straight line position it can intersect the parabola in none point, or one point or two points.