coucou
a) 5*-10(2-10)+(2-10-3)(4-7*-10)
= -50(2-10) -11*74
=-50*-8 - 814
=400 -814
= -414
b) 2(4+1/5)(1-3*1/5)-(7*1/5+2)(5-1/5)
=2(20/5+1/5)(5/5-3/5)-(7/5+10/5)(25/5-1/5)
=2*21/5*2/5-17/5*24/5
=42/5*5/5+7/5
=225/25 +7/5
=9 +7/5
= 45/5 +7/5
= 52/5
= 10,4
voila j espere t avoir aider