Answer:
2x=10
Step-by-step explanation:
7x-14=21
x=5
2x=10 (divide both sides by two)
2x/2 10/2
x=5
Yky. we'd to provide the other options but to do this you need to +14 to both side. 21+14 then -14+14 cancel. so it's now
7x=35 then you divide 7 in both sides 7 cancels 35/7 =5
x=5