Bonsoir,
1)
(4*4) - (x*x)
= 4² - x²
2)
(4-x) (4+x)
IR
3)
x= 1
(4*4) - (1*1)
= 16-1 => 15
x = 3
(4*4) - (3*3)
= 16 - 9 => 7
x= 3/5
(4*4) - (3/5*3/5)
= 16 -9/25
= 400/25 -9/25 => 391/25
