When 4 times a number is subtracted from 7 times the number, the result is 30.

Question

which one is correct?

{3, -15, 10, or 0.9

Answer 1

7 n - 4 n = 30
3 n = 30
n = 10

Answer 2

let the number be a 7a-150=0 ; 7a=150 divide by coefficient of a 7a/7=150/7 a=21.4