Rozwiąż równanie

a) x + 6 = 4


b) -2=x+5


c) 5x+11=21


d) 8c-9+4c-5+2c=7


e) 5+2y=17


f) 3a-4+2a+3=19


g) 5b+5-b-10=13


h) 5d-11-d+8=0


Odpowiedź :

a) x + 6 = 4

x =4 - 6

x = -2

b) -2 = x + 5

-2 - 5 = x

x = -7

c) 5x + 11 = 21

5x = 21 - 11

5x =  10    /:5

x = 2

d) 8c -9 + 4c -5 + 2c = 7

8c + 4c + 2c = 7 + 9 + 5

14c = 21  /: 14

c = 21/14

c = 3/2

e) 5 + 2y = 17

2y = 17 - 5

2y = 12   /:2

y = 6

f) 3a + 2a = 19 + 4 - 3

5a = 20  /: 5

a = 4

g) 5b - b = 13 - 5 + 10

4b = 18   /:4

b = 18/4

b = 9/2

h) 5d - d = -8 + 11

4d = 3   /: 4

d = 3/4