<u />{(x+y)/2=7
{x²-y²=14
↓
{(x+y)=7*2
{(x-y)(x+y)=14
↓
{x+y=14
{(x-y)*14=14
↓
{x+y=14
{x-y=1
↓(метод сложения)
{x+y+(x-y)=14+1
{x-y=1
↓
{2x=15
{y=x-1
↓
{x=7.5
{y=7.5-1=6.5
1,6x + 32,6 = 0,9x + 26,3
1,6x - 0,9x = 26,3 - 32,6
0,7x = - 6,3
<span>x = - 9</span>
15/10=3/2=1 1/2
1 1/2 * 3/2=3/2*3/2=9/4=2 1/4
(√28-√7)*√7=√28*√7-√7*√7=2√7*√7-(√7)²=
=2*7-7=14-7=7