تمارين مع الإصلاح

C1: \( (2x + 1)^2 - (3x - 2)(3x + 2) \)
الإصلاح:
\[ \begin{align*} (2x + 1)^2 - (3x - 2)(3x + 2) &= 4x^2 + 4x + 1 - [9x^2 - 4] \\ &= 4x^2 + 4x + 1 - 9x^2 + 4 \\ &= -5x^2 + 4x + 5 \end{align*} \]
C2: \( (2x + 3)^2 - (2x + 3)(x - 7) \)
الإصلاح:
\[ \begin{align*} (2x + 3)^2 - (2x + 3)(x - 7) &= 4x^2 + 12x + 9 - [2x^2 - 14x + 3x - 21] \\ &= 4x^2 + 12x + 9 - 2x^2 + 14x - 3x + 21 \\ &= 2x^2 + 23x + 30 \end{align*} \]
C3: \( 3(7x - 4)^2 - (x + 2)^2 \)
الإصلاح:
\[ \begin{align*} 3(7x - 4)^2 - (x + 2)^2 &= 3(49x^2 - 56x + 16) - [x^2 + 4x + 4] \\ &= 147x^2 - 168x + 48 - x^2 - 4x - 4 \\ &= 146x^2 - 172x + 44 \end{align*} \]
C4: \( (7x - 2)(3x + 1) - 2(2x + 1)^2 \)
الإصلاح:
\[ \begin{align*} (7x - 2)(3x + 1) - 2(2x + 1)^2 &= 21x^2 + 7x - 6x - 2 - 2[4x^2 + 4x + 1] \\ &= 21x^2 + x - 2 - 8x^2 - 8x - 2 \\ &= 13x^2 - 7x - 4 \end{align*} \]
C5: \( 5(3x - 9)(3x + 9) - (3x + 4)^2 \)
الإصلاح:
\[ \begin{align*} 5(3x - 9)(3x + 9) - (3x + 4)^2 &= 5[9x^2 - 81] - [9x^2 + 24x + 16] \\ &= 45x^2 - 405 - 9x^2 - 24x - 16 \\ &= 36x^2 - 24x - 421 \end{align*} \]
C6: \( (2x - 1)^2 - (2x + 3)(2x - 5) \)
الإصلاح:
\[ \begin{align*} (2x - 1)^2 - (2x + 3)(2x - 5) &= 4x^2 - 4x + 1 - [4x^2 - 10x + 6x - 15] \\ &= 4x^2 - 4x + 1 - 4x^2 + 10x - 6x + 15 \\ &= 16 \end{align*} \]
C7: \( (3x + 1)^2 - 2(3x - 1)^2 \)
الإصلاح:
\[ \begin{align*} (3x + 1)^2 - 2(3x - 1)^2 &= 9x^2 + 6x + 1 - 2[9x^2 - 6x + 1] \\ &= 9x^2 + 6x + 1 - 18x^2 + 12x - 2 \\ &= -9x^2 + 18x - 1 \end{align*} \]
C8: \( 2(2 - 14x)^2 - (7x - 1)^2 \)
الإصلاح:
\[ \begin{align*} 2(2 - 14x)^2 - (7x - 1)^2 &= 2(4 - 56x + 196x^2) - [49x^2 - 14x + 1] \\ &= 8 - 112x + 392x^2 - 49x^2 + 14x - 1 \\ &= 343x^2 - 98x + 7 \end{align*} \]
C9: \( 2x(x - 5) - (x + 1)^2 \)
الإصلاح:
\[ \begin{align*} 2x(x - 5) - (x + 1)^2 &= 2x^2 - 10x - [x^2 + 2x + 1] \\ &= 2x^2 - 10x - x^2 - 2x - 1 \\ &= x^2 - 12x - 1 \end{align*} \]
C10: \( (x + 3)^2 - (2x + 1)(2x - 1) \)
الإصلاح:
\[ \begin{align*} (x + 3)^2 - (2x + 1)(2x - 1) &= x^2 + 6x + 9 - [4x^2 - 1] \\ &= x^2 + 6x + 9 - 4x^2 + 1 \\ &= -3x^2 + 6x + 10 \end{align*} \]
C11: \( 5x^2 - (x + 3)(x - 3) \)
الإصلاح:
\[ \begin{align*} 5x^2 - (x + 3)(x - 3) &= 5x^2 - [x^2 - 9] \\ &= 5x^2 - x^2 + 9 \\ &= 4x^2 + 9 \end{align*} \]
C12: \( (3x + 2)^2 - (x - 1)^2 \)
الإصلاح:
\[ \begin{align*} (3x + 2)^2 - (x - 1)^2 &= 9x^2 + 12x + 4 - [x^2 - 2x + 1] \\ &= 9x^2 + 12x + 4 - x^2 + 2x - 1 \\ &= 8x^2 + 14x + 3 \end{align*} \]
C13: \( 5(x - 1)(x + 2) - (x + 3)^2 \)
الإصلاح:
\[ \begin{align*} 5(x - 1)(x + 2) - (x + 3)^2 &= 5(x^2 + 2x - x - 2) - [x^2 + 6x + 9] \\ &= 5x^2 + 10x - 5x - 10 - x^2 - 6x - 9 \\ &= 4x^2 - x - 19 \end{align*} \]
C14: \( (4x - 3)^2 + 7(x - 2)(x - 5) \)
الإصلاح:
\[ \begin{align*} (4x - 3)^2 + 7(x - 2)(x - 5) &= 16x^2 - 24x + 9 + 7[x^2 - 5x - 2x + 10] \\ &= 16x^2 - 24x + 9 + 7x^2 - 35x - 14x + 70 \\ &= 23x^2 - 73x + 79 \end{align*} \]
C15: \( -3(x - 6)^2 - 7(3x - 4)(3x + 4) \)
الإصلاح:
\[ \begin{align*} -3(x - 6)^2 - 7(3x - 4)(3x + 4) &= -3[x^2 - 12x + 36] - 7[9x^2 - 16] \\ &= -3x^2 + 36x - 108 - 63x^2 + 112 \\ &= -66x^2 + 36x + 4 \end{align*} \]