Respuesta :

Answer:

20

Step-by-step explanation: 20 doubled is 40 and 40 - 10 is 30

Answer:

20

Step-by-step explanation:

2x-10=30

Add 10 to both sides.

2x-10+10=30+10

2x=40

Divide both sides by 2.

2x/2=40/2

x=20