A.  5 + x = 30

<=> x = 30 - 5

<=> x = 25

Proef:

LL = RL = 25

D.  -x + 4 = 12

<=> -x = 12 - 4

<=> -x = 8

<=> x = -8

Proef:

LL = RL = 12

G.  -2x = -16
<=> x = -16/-2

<=> x = 8

Proef:

LL = RL = -16

B.  x - 7 = 14

<=> x = 14 + 7

<=> x = 21

Proef:

LL = RL = 14

E.  23 = 7 - x

<=> 7 - x = 23

<=> -x = 23 - 7

<=> -x = 16

<=> x = -16

Proef:

LL = RL = 23

H.  28 = -7x

<=> -7x = 28

<=> x = 28/-7

<=> x = -4

Proef:

LL = RL = -4

C.  13 + x = 7

<=> x = 7 - 13

<=> x = -6

Proef:

LL = RL = 7

F.  8x = 48

<=> x = 48/8

<=> x = 6

Proef:

LL = RL = 48

I.  39 = 3x

<=> 3x = 39

<=> x = 39/3

<=> x = 13

Proef:

LL = RL = 39