PLEASE EXPLAIN HOW DO THISSS

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

2x minus y equals 6, x plus y equals negative 3

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?