3,5^2=12,25>12
sqrt(12)<3,5
(3sqrt(5))^2=45<49
3sqrt(5)-7<0
<span>( √ 12 - 3,5 )* ( 3 √ 5 - 7 ) >0</span>
5-4x<0
4x>5
x>5/4
10х=120-20 10х=100 х=100:10=10
4у=8 у=8:4=2
25х+5=55 25х=55-5 х=50:25=2
7х-7=0 7х=7 х=7:7=1
{x=1 или {у=-4
{y²+y-2=0 или {16-4x-2=0
D=1+8=9
{x=1 {x=1 {y=-4
{y=-2 или {у=1 {x=3,5
О т в е т. (1;-2) (1;1) (3,5;-4)
100( 6a - 3b )^2 - 81( 3a + 2b )^2 = ( 10( 6a - 3b ))^2 - ( 9( 3a + 2b ))^2 =
= ( 60a - 30b )^2 - ( 27a + 18b )^2 = ( 60a - 30b + 27a + 18b )( 60a - 30b -
- 27a - 18b ) = ( 87a - 12b )( 33a - 48b )