There is no solution to this problem. Why? Well, see below for an explanation!
We can initially solve this problem using PEMDAS. Where we go wrong will be identified later. The P stands for Parenthesis, but there are none in this equation so we can skip that step. Next is E, which stands for Exponents. We do have an exponent, but it is separate from the problem. That would deem the problem invalid to solve because there is no base number for the exponent to be solved. Disregarding the exponent, we can solve by using M, which means Multiplication.
2 x 7 = 14
Next step, we can simplify to make the equation a tad bit neater.
3 + 14 - 30
Next up is D, meaning we need to divide. There are no numbers to divide though, so this step can be skipped.
Next step would be A, meaning we need to add.
3 + 14 = 17
Next step, we can simplify to make the equation neater as stated above.
17 - 30
17 - 30 = -13.
Disregarding the exponent, your answer would be -13. Including the exponent, however, would make the equation irrelevant. If you need extra help understanding this, let me know and I will gladly assist you.