D. Calculaţi: 1. 9-5-(7-13)-(5-[6+(3-9)-3]+12}= 2. 4-3-{5+[6-7-(3-5+9)+(3-7)]}= 3. 13-{14-15+[(16-17)+2-5]-(-5+7)}= 4. -9+{5-9-[13-(4-8)+(7+3-12)]-(-9)}=​