Question

a^2-b^2=12 si a+b=3 , atunci a-b = ....
Vă rog frumos !! .

Answer 1

a² - b2 = 12
(a + b)(a - b) = 12
a + b = 3
3(a - b) = 12
a - b = 12 : 3
a - b = 4

Answer 2

formula a² -b²=(a-b)(a+b)
a+b=3
inlocuim in formula
a² -b²=(a-b)x3
 a²-b²=12
12=(a-b)x3
(a-b)x3=12
a-b=12 :3
a-b=4

(a-b)(a+b)=12
3x4=12
12=12