Explicație pas cu pas:
[tex]2 {x}^{2} - 5 {x}^{2} + 7 {x}^{2} = (2 - 5 + 7) {x}^{2} = 4 {x}^{2} \\ [/tex]
[tex] - 2.7ab + 5ab = ( - 2.7 + 5)ab = 2.3ab \\ [/tex]
[tex]2x \times ( - 3x) = - 6 {x}^{2} [/tex]
[tex]( - 2 {x}^{2}y) \times ( - 3xy {z}^{2}) = 6 {x}^{3} {y}^{2} {z}^{2}[/tex]
[tex]{( - 2xy)}^{3} = - 8 {x}^{3} {y}^{3} [/tex]
[tex]( - 12 {a}^{3}b{c}^{3}) : (3abc) = - 4 {a}^{2} {c}^{2}[/tex]
