Hej!
a]
15x + 19 = 10
15x = 10 - 19
15x = -9 || : 15
x = -9/15 = -3/5
b]
20x + 7 = 31
20x = 31 - 7
20x = 24 || : 20
x = 1,2
c]
to nie równanie
d]
to też nie równanie
e]
-7(x - 2) = 3x - 1
-7x + 14 = 3x - 1
-7x - 3x = -1 - 14
-10x = -15 || : (-10)
x = 1,5
f]
4(x - 1) = 6(1 + x)
4x - 4 = 6 + 6x
4x - 6x = 6 + 4
-2x = 10 || : (-2)
x = -5
g]
1/5x - 2 = 4
1/5x = 4 + 2
1/5x = 6 || • 5
x = 30