<span> If the model is good, then both points will check in the equation. Substituting 8 for </span>x <span>and 5 for </span>y<span> 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 </span>y<span>-intercept should be –3/5.</span>