-3x(2xy + 3y – 2x)] ?

Question

Give an example of using the distributive property for a negative monomial times a trinomial with different signs on the terms [for example: -3x(2xy + 3y – 2x)] and show each step of the distribution. Why do you think many students make sign errors on this type of problem? What would be your advice to a student who has trouble with the signs?

Answer 1

-3x(2xy + 3y – 2x)

= -6xy^2 - 9xy + 6x^2

Remember...

(-) x (-) = (+)

(+) x (+) = (+)

(-) x (+) = (-)

Also, remember to  multiply both the numbers and the variables together

Answer 2

-3x(2xy + 3y - 2x)....

solution...

[(-3x * 2xy) + (-3x * 3y) - (-3x * 2x)}....distribute -3x inside the parenthesis

-6x^2y + 9xy + 6x^2....answer

most students creates errors in the signs due to the pressure or they might not haven't reviewed their answers...

enable to minimize these errors just review each steps and practice more in this field of mathematics...

that's it...