CBSE Class 10 Answered

Find x and y: $square root of x plus square root of 10 x plus y end root equals 21 comma x plus y equals 31.$

Asked by gudduage16 | 21 Dec, 2018, 08:31: AM

Expert Answer

x+y=31

or,y=31-x.

$begin mathsize 18px style square root of straight x plus square root of 10 straight x plus straight y end root equals 21 square root of straight x plus square root of 10 straight x plus 31 minus straight x end root equals 21 21 minus square root of straight x equals square root of 9 straight x plus 31 end root squaring 441 minus 42 square root of straight x plus straight x equals 9 straight x plus 31 441 minus 31 minus 42 square root of straight x plus straight x minus 9 straight x equals 0 410 minus 42 square root of straight x minus 8 straight x equals 0 8 straight x plus 42 square root of straight x minus 410 equals 0 4 straight x plus 21 square root of straight x minus 205 equals 0 4 straight x plus 41 square root of straight x minus 20 square root of straight x minus 205 equals 0 4 square root of straight x open parentheses square root of straight x minus 5 close parentheses plus 41 open parentheses square root of straight x minus 5 close parentheses equals 0 open parentheses square root of straight x minus 5 close parentheses open parentheses 4 square root of straight x plus 41 close parentheses equals 0 square root of straight x equals 5 straight x equals 25. end style$