Question

3.Calculati
a) - 20+21-22+33-24+25
b)-1+3-5+7-9+11-13+15
c)2-4+6-8+10-12+...+98-100
4. Calculati x-y-z+t daca:
x=-3-(-4)+(-5)-(-6)-(+2)
y=-1+(-4)-(-2)-(-4)+(-6)
,z=-3+(-6)-3-5+(-6)-(-3)
t=-11+(-3)-(-6)+(-8)-(-2)


Va rog ajutati-ma dau 30 de puncte +funda

Answer 1

a, 53 sper ca te-am ajutat pe b nu îl stiu

Answer 2

3.a) - 20+21-22+33-24+25 = 1-22+33-24+25 = -21+33-24+25 = 12-24+25 = 13
b) -1+3-5+7-9+11-13+15 = 2-5+7-9+11-13+15 = -3+7-9+11-13+15 = 4-9+11-13+15 = -5+11-13+15 = 6-13+15 = -7+15 = 8
c) 2-4+6-8+10-12+...+98-100 = 2(1-2+3-4+5-6+...+ 49-50)  imi pare rau, dar aici nu stiu cum sa continui 
4. x = -3+4-5+6-2 = 1-5+6-2 = -4+6-2 = 2-2 = 0
    y = -1-4+2+4-6 = -5+2+4-6 = -3+4-6 = 1-6 = -5 
    z = -3-6-3-5-6+3 = -9-3-5-6+3 = -12-5-6+3 = -17-6+3 = -23+3 = -20 
    t = -11-3+6-8+2 = -14+6-8+2 = -8-8+2 = -16+2 = -14 
x-y-z+t = 0-(-5)-(-20)+(-14) = 5+20-14 = 25-14 = 11 
Sper ca nu am gresit ceva