1. 3(-2)a - 2(-2)(a+3) = 18
-6a + 4(a +3) = 18
-6a + 4a + 12 = 18
-2a = 18 - 12
-2a = 6
a = 6/-2
a = -3
2. 7a (-1) + 15 = 2(-1)(a-1) +23
-7a + 15 = -2(a-1) + 23
-7a = 23 -15 -2a +2
-7a + 2a = 10
-5a = 10
a = 10/-5
a = -2
4. (x-2)la put 2 - 7= 2
(x-2) la put.2 = 7-2
(x-2) la put.2 = 5
x-2 = +/- 5
Se ia cazul x-2 = +5
x=5 +2
x = 7
Se ia cazul x-2 = -5
x = -5 +2
x= -3
S are solutii -3 si 7
7. m*3 -4*3 + 3 = 2(m-3) +7
3m -12 +3 = 2m -6 +7
3m -9 = 2m +1
3m - 2m = 1 +9
m = 10