№9
1) а)√1369 - √1681 = 37 -41 = -4
б) 2√0,1156 - √0,4761 = 2* 0,34 - 69 = -68,32
в) 0,4√441 + √2,56 = 0,4* 21 + 1,6 = 10
2) а) 5/√4225 - √25/169 = 5/65 - 5/13 = 5/65 + 25/65 = 30/65 = 6/13
б) 1/√361 + √6,25 = 1/19 + 2,5 = 10/190 + 375/190 = 385/190 = 77/38
в) √1369 - 2 *37 *29 +841 = √1369 - 74*29 + 841 = √1369 - 2116 +841 = 37 -46 + 29 = 20
№10
1)а) 6√x = 5
√x = 5/6
x = 25/36
б) √7x = 1
7x = 1
x = 1/7
в) 1/3√x = 3
√x = 3/1/3
x = 9/1/9
x = 81
г) (√x)^2 = 9
x =9
2) а) √x +1 =2
√x = 1
x = 1
б)3/√x-5 =4
√x-5 = 12
√x = 17
x = 289
в) 15/√x-3 = 3
√x -3 =15*3
√x = 45 +3
√x = 48
x = 2304
г) √2 +√3 +√x = 2
√x = 2 -4 -9
√x = -11
x = 121