Question

Devon wants to write an equation for a line that passes through 2 of the data points he has collected. The points are (8, 5) and (–12, –9). He writes the equation 7x – 10y = 3. Is this a good model? Explain your reasoning .

Answer 1

Step-by-step explanation:

Points are (8,5) and (-12,-9)

The equation of a line passing through two points is given by :

$y-y_1=m(x-x_1)\ \text{m is slope}\\\\y-5=\dfrac{y_2-y_1}{x_2-x_1}(x-8)\\\\y-5=\dfrac{-9-5}{-12-8}\times (x-8)\\\\y-5=\dfrac{7}{10}\times (x-8)\\\\10y-50=7x-56$

or

$-50+56=7x-10y\\\\7x-10y=6$

But he writes the equation 7x – 10y = 3 which is not matching with the one we have calculated. It means that model calculated by Devon is not good.

Answer 2

Answer:

If the model is good, then both points will check in the equation. Substituting 8 for x and 5 for y in the equation results in 56 – 50 = 3, which is not true. Therefore, the model is not good. Using (–12, –9) as a check results in –84 + 90 = 3. The constant value in the equation should be 6, not 3. In slope-intercept form, the y-intercept should be –3/5.

Step-by-step explanation:

i got this answer from edg