Math/Physic/Economic/Statistic Problems
Answer the following questions and state what Drew did wrong in each question:
The following exercises were given to the class. Drew quickly finished the work on the exercises and submitted them to the drop box. The problem is that his answers are wrong. Where did Drew go wrong? AND what is the correct answer for each?
Factor 81-x^2
Drew’s answer: (9-〖x)〗^2
2. Simplify x^2/3x-(6x^2)/2
Here’s what Drew did. x^2/3x-(6x^2)/2 = x^2-2/2 = x^2-1
Drew’s answer: x^2 – 1
Graph 2y = 3x + 4
Drew’s graph goes through 4 on the y-axis, since 4 is in the place of b in the slope-intercept form, y = mx + b. He also used 3/1 as the slope, since 3 is in the place of m. So from 4 on the y-axis, he went up three and to the right 1 to put another point. Then he drew his line through (0,4) and (7,1).
Solve 5x+8=3x-10
Here’s what Drew did: 5x-3x=10-8
2x=2 so x=1
Drew’s answer: x = 1
Why did Drew answer the question wrong/