Help simplify 3(2x-7)-x(5-x) please?!?

you need to do the distributive property...that means you mult what is out side of the equasion to what is inside.....seperate the problem in half....start with the first half

3(2x-7)

3times2x is 6x.

3 times -7 is -21

now, do the same for the second half

-x(5-x)

-x times 5 is -5x

-x times -x is x^2 (squared is ^2...that is how u write it...just in case u dont know)

So, now you have 6x-21-5x+x^2

you need to combine like terms..this means if the end is the same, put them together

6x and -5x have the same end...so you combine 6-5 is 1 keep the x...so now you have -21 + x + x^2

I like to visualise it differently, so i switch it around so it reads x^2 + x - 21

Multiply like this

3(2x-7) - x(5-x) = 3*2x - 3*7 - (x*5 - x*x)

= 6x -21 - 5x +x^2

= x^2 +x -21

(x-7)(x+3)

6x-21-5x-(x square)

-x-21-(xsquare)

(-xsquare)-x-21

pls choose this best answer pls its my humble request 2 u!!!!!