15/4-7x= 9
Move 15/4 to the other side. Sign changes from +15/4 to -15/4
15/4-15/4-7x= 9-15/4
-7x=9-15/4
Find the common denominator for 9 which is 4. Multiply by 4 .
9(4)= 36
36/4-15/4= 21/4
-7x= 21/4
Multiply by -1/7x on both sides
-7(-1/7)x= 21/4(-1/7)
Cross out 21 and -7 , divide by 7
21/7=3
-7/7=-1
3/4*-1/1= -3/4
Answer: -3/4