Respuesta :
Answer:
x = a number
7 + 2x = 21
Subtract 7 from both sides
2x = 14
Divide both sides by 2
x = 7
7 is the only number that makes this sentence true.
Step-by-step explanation:
Answer:
7
Step-by-step explanation:
Do the steps in reverse
Subtract 7 from 21
14
Then divide by 2
7
Hope this helps :)
Please consider Brainliest :)