Answer to:
(a - 3b)(2a - 5b)

distributive form

When I look at a problem like this, I think of the FOIL method. This method states "You multiply integers in the order of First, Outside, Inside, Last, and then add them  together"

(a -3b)(2a - 5b)

First --- 2a * a
Out  --- (-5b) * a
In     --- (-3b) * 2a
Last --- (-3b) * (-5b)

2a² - 5ab -6ab + 15b²

2a² - ab + 15b²

This would be your answer in simplest form!

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm

I'll do the first one for you. it isn't very hard at all.on number one, you have (50 × 3), which equals 150, and (3 × 3), which equals 9. after you establish that, you add 150 and 9 together. so, (150 + 9) equals 159.this means that 53 × 3 = 159.