The above question is a question from Algebra. It is a very important branch of mathematics which deals with structure, relationships and quantities of numbers.
Your question is about solving the equation X squared Plus 7 equals 43. It can be mathematically written as:
x2 +7 = 43
x2 = 43 -7
x2 = 36
Taking square root on both sides we get:
x = 6
which is the required answer for the above problem.