8. 70.5* 10. 30* 12. 5.1*
1.25 ¡Espero que esto te ayude!
<span> 8 - 4x=4 - 3(2x+6)
<=> 8 - 4x = 4 - 6x - 18
<=> 8 - 4 + 18 = 4x - 6x
<=> 22 = -2x
x = -11</span>
Since two people take both courses, we can subtract two from 7, 8, and 21, giving us 5, 6, and 19.
Add 5 and 6 together to get 11. Since eleven students are in those two groups, we can answer this. The answer will be 11/19.