Use slope formula to find slope
<span><span><span>−9−5</span><span>−/12−8</span></span>=<span><span>−14/</span><span>−20</span></span>=<span>7/10</span></span>
7/10 = m = slope y= mx + b
y= (7/10)x + b
(8,5)
(5) = (7/10)(8) + b
b = -3/5
So....
<span>y=(<span>7/10)</span>x −<span>35
</span></span>
multiply by 10
<span>10y=7x−6</span><span>
--> -7x + 10y = -6 --> 7x - 10y = 6
So, if 7x - 10y = 3 a good model?</span>
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. Hope this helps!!! :)