SOLUTION: When asked to solve the equation (x + 3)(2x - 1) = 5 a student proceeded as follows: x+3=5 or 2x-1=5 x=2 or x=3 Describe, in your own words, what this student did w

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: When asked to solve the equation (x + 3)(2x - 1) = 5 a student proceeded as follows: x+3=5 or 2x-1=5 x=2 or x=3 Describe, in your own words, what this student did w      Log On


   

Question 359440: When asked to solve the equation (x + 3)(2x - 1) = 5 a student proceeded as follows:
x+3=5 or 2x-1=5
x=2 or x=3
Describe, in your own words, what this student did wrong and what he/she should have
done.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
That would only work if their product equals 5 simultaneously.
So when one factor equals 5, the other equals 1.
When x%2B3=5, x=2, but 2%282%29-1=4, so then the product equals 5%2A4=20%7D%7D+and+not+%7B%7B%7B5 as expected.
When 2x-1=5, x=3, but 3%2B3=6, so then the product equals 5%2A6=30 and not 5 as expected.