Andrew factored the expression 28x^3-42x^2+35x as 7x(4x^2+6x-5). But when Melissa applied the distributive law and multiplied out 7x(4x^2+6x-5) , she got 28x^3+42x^2-35x ; thus, Andrew’s solution does not appear to check. Why is that? Please help Andrew to understand this better. Explain your reasoning and correctly factor the original expression, if possible.
Can someone please help me with this question.
Algebra - Julie, Tuesday, July 26, 2011 at 3:27am
The negative sign is misplaced, and must go before the 6x instead of the 5, making the correct factor: