2√7 < 7√2
√(2²*7) < √(7²*2)
√28 < √98
3√120=√(3²*120)=√(9*120)=√1080
2√270=√(2²*270)=√(4*270)=√1080
3√120=2√270
1/2*√6=√(1/4*6)=√(6/4)=√1,5
6√(1/2)=√(36*1/2)=√18
1/2√6<6√(1/2)
D = 9 - 4*2 = 1
x₁ = ( - 3 - 1)/2 = - 4/2 = - 2;
x₂ = ( - 3 + 1)/2 = - 2/2 = - 1;
+ - +
------------ [ - 2] -----------------[ - 1] --------------> x
x ∈ ( - 2; - 1)
1)(5a-10)/a²-4=5(a-2)/(a-2)(a+2)=5/a+2
2)(a²-2ab)/3a-6b=(a(a-2b))/(2(a-2b))=a/2
3) (a+3)³/5a²+15a=(a+3)³/(5a(a+3))=(a+3)²/5a
4)(m³-5m²n)/(mn²-5n)=(m²(m-5n))/(n²(m-5/n)
5)a²-6a+9/a²-9=((a-3)(a-3))/((a+3)(a-3))=(a-3)/(a+3)
6)a²-2a+1/a²-1=((a-1)(a-1))/((a+1)(a-1))=(a-1)/(a+1)