ex 1
10 exp 100 -10
= 10(10 exp 99 -1)
ex 2
1a) (x+1)²-(x-2)(x+2)
= x²+2x+1-(x²-4)
= x²+2x+1-x²+4
= 2x+5
b) 1001²-998×1002
=1001²-(1000-2)(1000+2)
=1001²-(1000²-4)
=1001²-1000²+4
=(1001-1000)(1001+1000)+4
=1(2001)+4
=2001+4
=2005
alors je te laisse essayer de continuer