tolong besok dikumpulin beneran deh yang dibuletin aja

1e. 7x =1  
x = 1/7

2c. Bukan, penyelesaian :
4n + 5 = 19
4n = 19 -5
4n = 14
n = 14/4
n = 2,5

3a. 3x + 4 = 7
3x = 7-4
3x = 3
x = 3/3
x = 1

4f. 7x - 15 = 6(x+2)
7x - 15 = 6x + 12
7x - 6x = 12 + 15
x = 27