Question

Помогите пожалуйстоооо

Answer 1

70.
1. Имеет
2.имеет
3.не имеет
4. Имеет
71.
$1)0.1 times 30 - frac{1}{4} times 8 = 3 - 2 = 1 \ 2)5 times 0.2 + sqrt{27 + 22} = 1 + sqrt{49} \ = 1 + 7 = 8$
$3)4 times 0.7 - sqrt{289} = 2.8 - 17 = \ - 14.2$
$4) sqrt{ frac{100}{49} } + sqrt{ frac{25}{9} } - 0.03 times 200 = \ frac{10}{7} + frac{5}{3} - 6 = 1 frac{3}{7} + 1 frac{2}{ 3} - 6 =$
$1 frac{9}{21} + 1 frac{14}{21} = 2 frac{23}{21} = 3 frac{2}{21} - 6 = \ 3 frac{2}{21} - 5 frac{21}{21} = - 2 frac{19}{21}$
72.
$1)7 - 1.1 = 5.9 \ 2)48 - 45 = 3 \ 3)32 times ( - frac{1}{4} times 11) - frac{1}{3} times 735 =$
$32 times ( - frac{11}{4} ) - 245 = \ - 88 - 245 = - 333$
$4)28 - frac{1}{49} times 343 = 28 - 7 = 21$
73.
1)при а=9
2)при а=3
3)при а =5
4)не знаю
5)при а =-5
6)не знаю
74.
$1) sqrt{x } = 7 \ x = 49 \ 2) sqrt{x} = frac{4}{5}$
$x = frac{16}{25}$
$3) sqrt{x} = 5 \ x = 25$
$4)3 sqrt{x} = 8 \ sqrt{x} = 8 div 3 = frac{8}{3} \ x = frac{64}{9} = 7 frac{1}{9}$
$5) frac{1}{2} sqrt{x} = - 3 \ sqrt{x} = - 3 div frac{1}{2} = - 6$
Нет решения
$6) sqrt{5x} = 6 \ 5x = 36 \ x = 36 div 5 = 7.2$
$7)5x - 6 = 0 \ 5x = 6 \ x = 6 div 5 \ x = 1.2$
$8)5x - 6 = 1 \ 5x = 1 + 6 = 7 \ x = 7 div 5 = 1.4$
$9) 24 = 12 sqrt{x} \ sqrt{x} = 24 div 12 = 2 \ x = 4$
Умножили обе части на корень из х
$10)12 = 4( sqrt{x - 3} ) \ 4 sqrt{x} - 12 = 12 \ 4 sqrt{x } = 12 + 12 = 24 \ sqrt{x} = 24 div 4 = 6 \ x =$
$x = 36$
$11)2 + sqrt{2 + sqrt{x} } = 4 \ sqrt{2 + sqrt{x} } = 4 - 2 = 2 \ 2 + sqrt{x} = 4$
$sqrt{x} = 4 - 2 = 2 \ x = 4$
$12)2 sqrt{ {x}^{2} - 9} = - x \ 4( {x}^{2} - 9) = {x}^{2} \ 4 {x}^{2} - 36 - {x}^{2} = 0 \ 3 {x}^{2} = 36 \ {x}^{2}$
${x}^{2} = 12 \ x = - + sqrt{4 times 3} = - + 2 sqrt{3}$
75.
$1)x = + - 3 \ 2)x = + - sqrt{13}$
$3) {x}^{2} + 2x + 1 = 0 \ d = 4 - 4 = 0 \ x = frac{ - 2 - 0}{2} = - 1$
Либо
$x + 1 = 0 \ x = - 1$
4)нет решения
$5) {x}^{2} - 4x + 4 - 64 = 0 \ {x}^{2} - 4x - 60 = 0 \ d = 16 + 240 = 256 = 16$
$x1 = frac{4 + 16}{2} = frac{20}{2} = 10 \ x2 = frac{4 - 16}{2} = - frac{12}{2} = - 6$
$6) {x}^{2} + 10x + 25 - 2 = 0 \ {x}^{2} + 10x + 23 = 0 \ d = 100 - 92 = 8 = 2 sqrt{2}$
$x1 = frac{ - 10 - 2 sqrt{2} }{2} = frac{ - 2(5 + sqrt{2} )}{2} = \ = - 5 - sqrt{2}$
$x2 = frac{ - 10 + 2 sqrt{2} }{2} = frac{ - 2(5 - sqrt{2}) }{2} = \ = - 5 + sqrt{2}$
76.
1)4
2)не знаю
3)-2