Jawabanmu

2014-08-21T18:55:59+07:00
A. (m+3)(m-7)
= m(m-7) + 3(m-7)
= m^{2}  - 7m + 3m - 21
= m^{2} - 4m - 21

b. (2y-5) (4y+10)
= 2y(4y+10) - 5(4y+10)
= 8 y^{2} + 20y - 20y - 50
= 8 y^{2} - 50
2014-08-21T19:05:29+07:00
(m +3)(m-7)
m² - 7m + 3m - 21
m² - 4m -21

(2y -5)(4y+10)
8y² + 20y - 20y - 50
8y² - 50