Unit 5 Online Self Quiz
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1. The number of points of intersection of the following graphs is three:
x2+ y2= 22x + y = 10
2. When solving this system graphically, the graphs are a line and a parabola.
x2 + 2y = -6
x - y = 3
3. Given:
x + 2y = 9
3x - 2y= -5
If the elimination method is used to solve the system, the next step would be:
x = -2y +9
4. If the total cost of running a business is given by the equation
C = 4.16x + 75,000
and the revenue is given by the equation
R = 7.91x,
find the sales necessary to break even.
x = 20,000
5. Solve the linear system by the method of elimination:
7x - 3y = 2
2x + 5y = 25
x = 3, y = 5
6. Find the value of y in the solution of the system of equations:
3x + 7y = 15
-5x + 2y = 16
y = -2
7. Suppose the demand and supply equations for a certain product are given by
p = 860 - 0.05x Demand equation
p = 420 + 0.15x Supply equation
then the equilibrium value is 420 units.
8. Use the method of back substitution to find the value of x for the solution of the system of equations.
x + 2y + z = 15
5y - 2z = -16
z = 3
9) Is (-1, 2, -2) the solution to the following the system of linear equations? Hint: store x,y and z in th graphics calculator. Ex 2 STO Alpha Y
x - 3y + 2z = -11
x + 4y - 5z = 17
-2x + y - z = 6
10) The system:
x + 3y = 9
2x + 6y = 32 has no solution.