Answer:
x = 4
Step-by-step explanation:
I'm not sure if this is correct since your question is incomplete.
7x + 3 = 10x - 9
Minus 3 on both sides
7x = 10x - 12
Minus 7x on both sides
0 = 3x - 12
Plus 12 on both sides
12 = 3x
Divide by 3 on both sides to isolate x
x = 4
Hope this helps :)
Have a nice day!