Maryjocel1viz
Answered

What is the answer in:

1. (2xy + 1) - (xy - 3)

2. (4x+1)+(5x-3)

Sagot :

2. (4x + 1)(5x - 3)

                           4x + 1
                           5x - 3
                         - 12x - 3
                  20x2 + 5x
Answer: 20x2 - 7x -3

why?
(+ 1) (- 3) = negative 3
(- 3)(4x) = negative 12x
(5x)(+1) = positive 5x
(4x)(5x) = 20x squared

then?
1. bring down - 3
2. - 12x + 5 = - 7x
3. bring down 20x squuared