Jawabanmu

2014-08-29T19:22:41+07:00
Ini cobak2.
a² - b² = 7² - 3² = 49 - 9 = 40 (benar)
a - b = 7 - 3 = 4 (benar)
jadi jawabannya : a + b = 7 + 3 = 10
1 5 1
2014-08-29T19:27:32+07:00
A² - b² = (a + b) x (a - b )
  40    = (a + b) x 4
(a + b)=40:4
(a + b)=10