bonjour,
A = ( 2 z + 3 )²
b = ( 4 r - 5 )²
c = ( 3 t - 8 ) ( 3 t + 8 )
d = ( 5 y - 7 )²
e = ( d - 4 ) ( d + 4 )
f = ( 3 a + 4 )²
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a = ( 3 p + 5 )²
b = ( s - 6 )²
c = ( 1 - e ) ( 1 + e)