Question

What is the correct simplification of the expression (-2x + 4y)(3x - 7y).

I got 6x-16xy-28y, Is it wrong? I used box method to get my answer.

Answer 1

your answer is wrong

Answer 2

x times x = x^2

Answer 3

Try FOIL: first, outside inside last.

example:

(-a+b)(c-d)
-ac + (-a)(-d) + bc + b(-d)
-ac + ad + bc -bd

combine like terms (which wont be possible with my example)
and that will give you the answer @CrazyC246

Answer 4

That's what I was thinking of doing. My teacher told that if i don't understand FOIL use the box method.

Answer 5

@CrazyC246 , I am not familiar with the box method but FOIL is pretty straight up, just gotta watch your signs and multiplication.

Answer 6

This is what I did.

Answer 7

@CrazyC246 , remember when multiplying two variables with exponents

x has an exponent 1
you add the exponents

x^1(x^1)=x^(1+1)=x^2