System of Equations — Quiz 3

Questions in this quiz (6)

1. Find the average of $$a$$, $$b$$, and $$c$$ given the system of equations below:$$a + b - c = 2$$$$2a - b + 2c = 10$$$$3a + b + 3c = 21$$

   • $$\frac{12}{5}$$
   • $$\frac{43}{5}$$
   • $$\frac{29}{10}$$
   • $$\frac{33}{10}$$

2. If $$(x - y)^2 = 64$$ and $$x^2 + y^2 = 100$$, what is the value of $$xy$$?

   • 64
   • 80
   • 36
   • 18

3. If $$x = 2y$$ and $$(x - 4)^2 + (y + 2)^2 = 20$$ how many ordered pairs $$(x, y)$$ satisfy the system of equations above?

   • 0
   • 1
   • 2
   • Infinity

4. If $$(a+b)^2=64$$ and $$a^2+b^2=34$$, what is the value of $$ab$$?

   • 32
   • 15
   • 17
   • 20

5. If $$a^2 - b^2 = 72$$ and $$a + b = 24$$, what is the value of $$a - b$$?

   • 72
   • 24
   • 12
   • 3

6. Given the system of equations below. How many solutions does it have?$$y = x^2 + 3x - 7$$$$y - 5x + 8 = 0$$

   • 0
   • 1
   • 2
   • 3