Răspuns :
Răspuns:
1.
a)
[tex]x - 2 = 5 \\ x = 5 + 2 \\ x = 7[/tex]
b)
[tex] - x + 3 = - 9 \\ -x = - 9 - 3 \\ - x = - 12 \: | \times ( - 1) \\ x = 12[/tex]
c)
[tex]2x - 5 = 3x - 4 \\ 2x - 3x = 5 - 4 \\ - x = 1 | \: \times ( - 1) \\ x = - 1[/tex]
d)
[tex] - 11x + 4 = - 3(3x + 2) \\ - 11x + 4 = - 9x - 6 \\ - 11x + 9x = - 4 - 6 \\ - 2x = - 10 \\x = - 10 \div ( - 2) \\ x = 5[/tex]
e)
[tex] - 2(x + 9) = - 18 \\ - 2x - 18 = - 18 \\ - 2x = 18 - 18 \\ - 2x = 0 \\ x = 0 \div ( - 2)\\ x = 0[/tex]
f)
[tex] - 5( - x + 4) + 6 = 1 \\ 5x - 20 + 6 = 1 \\ 5x - 14 = 1 \\ 5x = 14 + 1 \\ 5x = 15 \\ x = 15 \div 3 \\ x = 5[/tex]
2.
a)
[tex]x - 7 = - 8 + 1 \\ x - 7 = - 7 \\ x = 7 - 7 \\ x = 0[/tex]
b)
[tex]x + 3 = - x + 5 \\ x + x = - 3 + 5 \\ 2x = 2 \\ x = 2 \div 2 \\ x = 1[/tex]
c)
[tex]2x - 5 = 4x + 7 \\ 2x - 4x = 5 + 7 \\ - 2x = 12 \\ x = 12 \div ( - 2) \\ x = - 6[/tex]
d)
[tex] - 2x + 7 = x - 2 \\ - 2x - x = - 7 - 2 \\ - 3x = - 9 \\ x = - 9 \div ( - 3) \\ x = 3[/tex]
e)
[tex] - x + 2 - 2x = - 4x + 5 - 7 \\ - x - 2x + 4x = - 2 + 5 - 7 \\ x = - 4[/tex]
f)
[tex]5 + 2 - 3 + x = - 8 + x + 4 \\ 5 + 2 - 3 + 8 - 4 = - x + x \\ 8 = 0 \\ \: asta \: cred \: ca \: ai \: scris - o \: gresit \: ca \: nu \: are \: sens[/tex]