Explicație pas cu pas:
a)
[tex](3 + 8 - 2)x = 9x[/tex]
[tex](50 + 50 - 50)x = 50x[/tex]
[tex]{x}^{2} + 6x + {x}^{2} - 6x + 3 = ({x}^{2} + {x}^{2}) + (6x - 6x) + 3 = 2 {x}^{2} + 3[/tex]
[tex]{x}^{2} + 6x + 3 {x}^{2} + 7x + 4 =( {x}^{2} + 3 {x}^{2}) + (6x + 7x) + 4 = 4{x}^{2} + 13x + 4[/tex]
[tex]{x}^{3} + {x}^{2} - x + {x}^{3} - {x}^{2} + x =({x}^{3} + {x}^{3}) + ({x}^{2} - {x}^{2}) + (x - x) = 2 {x}^{2}[/tex]
b)
[tex](x + 5) - (2x + 4) = x + 5 - 2x - 4 = (x - 2x) + (5 - 4) = - x + 1[/tex]
[tex]( {x}^{2} + 3x + 1) - ( - 2{x}^{2} - 6x + 1) = {x}^{2} + 3x + 1 + 2{x}^{2} + 6x - 1 = ( {x}^{2} + 2{x}^{2} ) + (3x + 6x) + (1 - 1) = 3 {x}^{2} + 9x = 3x(x + 3)[/tex]
[tex]( - {x}^{3} + 4 {x}^{2} - 9) - (3{x}^{3} - 5 {x}^{2} + 1) = - {x}^{3} + 4 {x}^{2} - 9 - 3{x}^{3} + 5 {x}^{2} - 1 = (- {x}^{3} - 3{x}^{3}) + (4 {x}^{2} + 5 {x}^{2}) + ( - 9 + 1) = - 4{x}^{3} + 9{x}^{2} - 10[/tex]
