2 x + 3 equal to 5 find x​

Ineed with number 6 , explain how to get 1978

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Hell . what are the solutions to `10x^2 - 38x - 8 = 0`? is this when i find the factors and use the numbers within the factors to determine the zeros? i hope that made sense lol