7 Use the example as a model and simplify. - \( 3 x+6+x+2=3 x+x+6+2=4 x+8 \) \( \begin{array}{ll}\text { a) } 3 a+3-2 a+1 & \text { b) } 5 x+2-3 x+x \\ \text { c) } 7-4 a-7+5 a & \text { d) } 4 x-3-4 x+2 \\ \text { e) } x^{2}+4+x^{2}+1 & \text { f) } 5 x^{2}-3-4 x^{2}+1 \\ \text { g) } x^{2}+4 x+1+2 x+3 & \text { h) } 5 x^{2}+3 x-4 x^{2}-2 x+1 \\ \text { i) } 3 x^{2}+\frac{4}{5}-x^{2}+2 x-\frac{1}{5} \\ \text { j) } 10-\frac{3}{2} x+\frac{1}{2} x^{2}-7-x\end{array} \)

Claro, simplifiquemos cada expresión siguiendo el modelo proporcionado. **a) \( 3a + 3 - 2a + 1 \)** \[ 3a + 3 - 2a + 1 = (3a - 2a) + (3 + 1) = a + 4 \] **b) \( 5x + 2 - 3x + x \)** \[ 5x + 2 - 3x + x = (5x - 3x + x) + 2 = 3x + 2 \] **c) \( 7 - 4a - 7 + 5a \)** \[ 7 - 4a - 7 + 5a = (-4a + 5a) + (7 - 7) = a + 0 = a \] **d) \( 4x - 3 - 4x + 2 \)** \[ 4x - 3 - 4x + 2 = (4x - 4x) + (-3 + 2) = 0x -1 = -1 \] **e) \( x^{2} + 4 + x^{2} + 1 \)** \[ x^{2} + 4 + x^{2} + 1 = (x^{2} + x^{2}) + (4 + 1) = 2x^{2} + 5 \] **f) \( 5x^{2} - 3 - 4x^{2} + 1 \)** \[ 5x^{2} - 3 - 4x^{2} + 1 = (5x^{2} - 4x^{2}) + (-3 + 1) = x^{2} - 2 \] **g) \( x^{2} + 4x + 1 + 2x + 3 \)** \[ x^{2} + 4x + 1 + 2x + 3 = x^{2} + (4x + 2x) + (1 + 3) = x^{2} + 6x + 4 \] **h) \( 5x^{2} + 3x - 4x^{2} - 2x + 1 \)** \[ 5x^{2} + 3x - 4x^{2} - 2x + 1 = (5x^{2} - 4x^{2}) + (3x - 2x) + 1 = x^{2} + x + 1 \] **i) \( 3x^{2} + \frac{4}{5} - x^{2} + 2x - \frac{1}{5} \)** \[ 3x^{2} + \frac{4}{5} - x^{2} + 2x - \frac{1}{5} = (3x^{2} - x^{2}) + 2x + \left( \frac{4}{5} - \frac{1}{5} \right) = 2x^{2} + 2x + \frac{3}{5} \] **j) \( 10 - \frac{3}{2}x + \frac{1}{2}x^{2} - 7 - x \)** \[ 10 - \frac{3}{2}x + \frac{1}{2}x^{2} - 7 - x = \frac{1}{2}x^{2} + \left( -\frac{3}{2}x - x \right) + (10 - 7) = \frac{1}{2}x^{2} - \frac{5}{2}x + 3 \]