4) a) (7x + 1) − (6x + 3) = 5; б) (8x + 11) – 13 = 9x – 5; в) 2 = (3x - 5) - (7 - 4x); г) 8х + 5 = 119 + (7 - 3x).

Question

Accepted Answer

а) (7x + 1) − (6x + 3) = 5
\( 7x + 1 - 6x - 3 = 5 \)
\( x - 2 = 5 \)
\( x = 7 \)
б) (8x + 11) – 13 = 9x – 5
\( 8x + 11 - 13 = 9x - 5 \)
\( 8x - 2 = 9x - 5 \)
\( 5 - 2 = 9x - 8x \)
\( x = 3 \)
в) 2 = (3x - 5) - (7 - 4x)
\( 2 = 3x - 5 - 7 + 4x \)
\( 2 = 7x - 12 \)
\( 14 = 7x \)
\( x = 2 \)
г) 8х + 5 = 119 + (7 - 3x)
\( 8x + 5 = 119 + 7 - 3x \)
\( 8x + 5 = 126 - 3x \)
\( 8x + 3x = 126 - 5 \)
\( 11x = 121 \)
\( x = 11 \)

Ответ: а) \( x = 7 \); б) \( x = 3 \); в) \( x = 2 \); г) \( x = 11 \).