I don't understand why 6mn-4m... changed to 6mn+4m...
This same thing happened here. When + was added to -3 Why are the multiplication signs changing?

Everything inside the bracket was multiplied by negative sign outside the bracket. That's why 6mn changed to -6mn, and subsequently -4m^2n^3 changed to 4m^2n^3

- x - =+
- x + =-

chicoMX:
Everything inside the bracket was multiplied by negative sign outside the bracket. That's why 6mn changed to -6mn, and subsequently -4m^2n^3 changed to 4m^2n^3

thank you so much. I never knew that. Now, I understand. God bless you
.

Techcrunchng:
- x - =+ - x + =-

yes, I understand now God bless you

chicoMX:
Everything inside the bracket was multiplied by negative sign outside the bracket. That's why 6mn changed to -6mn, and subsequently -4m^2n^3 changed to 4m^2n^3

I understand the upper one now as the result came by multiplication.
What about this one I just highlighted? No multiplication took place here, yet (-3) was bracketed and a summation + sign precedes it. Where did the "+" come from? Can u explain the whole highlighted aspect in red, please?
I'm really sorry for the questions. I just started studying mathematics by myself the previous month (with no idea of any calculations before) , and I've been doing quiet well even in some more complex topics but this particular one I'm yet to understand.

Mustiboy:
I understand the upper one now as the result came by multiplication.
What about this one I just highlighted? No multiplication took place here, yet (-3) was bracketed and a summation + sign precedes it. Where did the "+" come from? Can u explain the whole highlighted aspect in red, please?
I'm really sorry for the questions. I just started studying mathematics by myself the previous month (with no idea of any calculations before) , and I've been doing quiet well even in some more complex topics but this particular one I'm yet to understand.

.
After multiplying out the bracket
You collect like terms, -3+6=3
If you multiply +(-3+6) you will still get -3+6
Nothing has taken place, it's just for convenience

chicoMX:
.
After multiplying out the bracket
You collect like terms, -3+6=3
If you multiply +(-3+6) you will still get -3+6
Nothing has taken place, it's just for convenience

oh! Beautiful! I wouldn't think of it that way if I wasn't thought. Thanks, bro.