3. ( √2+√50-√72)*√5-16/21:(-2/63)
(√2+5√2-6√2)*√5+16/21*63/2
0√5+8*3 = 0+24= 24
4. |2x-1|≤3
2x-1≤3, 2x-1≥0
-(2x-1)≤3,2x-1<0
x≤2,x≥1/2
x≤-1,x<1/2
x∈(1/2,2)
x∈(-1,1/2) rezulta ca x ∈ (-1,2)
a) 0 este element al multimii A x∈(-1,0,1,2)
b) [ -1,2] ( deseneaza intervalul )
5. E(x) = (x+1)²+2(x²+4x+3)+(x+3)²
E(x)=(x+1+x+3)²
E(x)=(2x+4)²
E(x) = (2(x+2))²
