Решите уравнение 7x²+21x=0 Упростите выражение 3m(2m-1)-(m+3)(m-2)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ #1  7x²+21x=0 7x*(x+3)=0 x*(x+3)=0 x=0           x₁=0 x+3=0       x₂=-3 ========================================================== #2 3m(2m-1)-(m+3)(m-2)= =6m²-3m-(m²-2m+3m-6)= =6m²-3m-(m²+m-6)= =6m²-3m-m²-m+6= =5m²-4m+6 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

7x²+21x=0 7x(х+3)=0 7х=0     х+3=0 х₁=0      х₂=-3 -------------------------------------------- 3m(2m-1)-(m+3)(m-2)=6m²-3m-(m²+3m-2m-6)= 6m²-3m-m²-m+6=5m²-4m+6