John bought three cars in the last year for a total of $30,000 he paid the same amount for each of the first two cars and got the third one for twice the amount of the first car which equation can be used to find out how much John paid for each car? Ignore sales tax
1.x(30,000)=2x
2.x + 2x=30,000
3.30,000x=x+2x
4.x+x+2x=30,000