Jawabanmu

2014-09-11T19:46:25+07:00
A. 20xy-100
b. (x+5) × (5x-1) = 5x² - x + 25x - 5
                           = 5x² + 24x -5 
c.(7-2x) × (2x-7) = 14x - 49- 4x² + 14x
                            = -4x² + 28x - 49
yg a salah soal kayaknya deh, harusnya 10 X (2y-10). jawabannya 20y-100
2014-09-11T19:51:30+07:00
A.(10x.2y) - (10x.10)
20xy - 100x
B.(x.5x) +(5.5x) + (x.-1) + (5.-1)
5x^2 + 25x + -x + -5
5x^2 + 24x - 5
C. (7.2x) + (7.-7) + (-2x.2x) + (-2x.-7)
14x + -49 + -4x^2 + 14x
-4x^2 + 14x + 14x -49
-4x^2 + 28x - 49
4 3 4