If a and B satisfy (3 radical a) + (5|b |) = 7, find the value range of S = (2 radical a) - (3|b |) There should be a reason

If a and B satisfy (3 radical a) + (5|b |) = 7, find the value range of S = (2 radical a) - (3|b |) There should be a reason

First of all, the absolute value B is a non negative number, and because negative numbers can not be used as arithmetic bungalow roots, so the absolute value B of 5 may be equal to 0 or 5. If it is equal to 0, the root sign a of 3 should be equal to 7, so it is impossible. If the absolute value B of 5 is equal to 5, then the root sign a of 3 should be equal to 2, then a should be equal to 8, The absolute value B of 5 is equal to 5, so B should be equal to plus or minus 1. It turns out that the absolute value B of 3 must be equal to 1. Root 8-1: root 8 is a number less than 3 and greater than 2, so the value range of S is greater than 1 and less than 2