Your formatting is very ambiguous and I'm struggling to figure out what exactly the problem is. I'm guessing this is one problem, where the 7i2 is the denominator of the fraction.
If I'm not correct, please correct me. The next thing I'm assuming is that i in this problem is the imaginary number, rather than a variable. If it's the imaginary number, then i2 has a constant value. Do you know what that value is? As a hint, the imaginary number is defined as the square root of -1. By extension, then, what is i4? Once you have the i terms taken care of, you can tackle the numerator.
Do you remember your exponent rules? Like, \(\displaystyle \left(a\cdot b\right)^c=?\) and \(\displaystyle \left(x^a\right)^b=?\). Hopefully this is enough of a hint to get you started. If you get stuck again, please include all of your steps and workings when you reply back.