7. The equation of the line passing through the pair of points
(0,-2) and (2,5) is:

c. y = 3x - 2

Nope, Let's try this by hand and then by calculator. First, by hand, we find the slope by using this formula: (y2 - y1)/(x2 - x1). In our case we have [5 - (-2)]/(2 - 0) = 7/2 = 3.5. So, we need a linear equation which has a slope of 3.5, but the equation in choice c only has a slope of 3. Now lets try this using our calculator:

Casio 300W                 Sharp EL-531R

 

 

 

 

 

 

 

 

 

 

 

Casio 300W

  • Turn on your calculator by pressing [ON]
  • Put your calculator in LR mode by pressing Mode [3] [1]
  • Clear your statistical Memory by pressing [SHIFT] [AC] [=]
  • To enter the first data point, press [0] [,] [(-)] [2] [M+]- the comma button is just above the red DEL key.
  • To enter the second data point, press [2] [,] [5] [M+]
  • To find the y-intercept (a) of the linear equation, press [SHIFT] [7]
  • To find the slope (b) of the linear equation, press [SHIFT] [8]
  • The equation for the line that passes through these two slopes is y = a + bx, where you replace a and b with the values you just calculated.

Question #8

 

 

 

 

 

 

 

 

 

 

 

 

Sharp EL-531R

  • Turn on your calculator by pressing [ON/C]
  • Put your calculator in variable 2 mode by pressing Mode [2ndF] [DRG] [2]
  • Clear your statistical Memory by pressing [2ndF] [DEL]
  • To enter the first data point, press [0] [STO] [+/-] [2] [M+]- your display will read n = 1.
  • To enter the second data point, press [2] [STO] [5] [M+]
  • To find the y-intercept (a) of the linear equation, press [RCL] [(]
  • To find the slope (b) of the linear equation, press [RCL] [)]
  • The equation for the line that passes through these two slopes is y = a + bx, where you replace a and b with the values you just calculated.

 

Question #8