2 часа, с остатком 14 минут
1) 121/2 - 2= 60 1/2-2=58 1/2
2) 1/5- 1/40= 8/40-1/40= 7/40
3) 2+62/3= 2+20 2/3= 22 2/3
4) 15/6-12/3= 15/6-22/6= -7/6= -1 1/6
5)58 1/2 : 7/40= 117/2 * 40/7= 117/1 * 20/7= 2340/7
6) 2330/7-22 2/3= 2340/7 -68/3= 7020/21-476/21 = 6544/21
7) 6544/21 : (-1 1/6)= - 6544/21 * 6/7= - 6544/2 * 2=- 13088/7
8) - 13088/7 * 3/8= - 1638/7 *3= - 4908/7= -701 1/7
(2.48)^2-2•0.48•2.48+(0.48)^2=(2.48-0.48)^2=2^2=4
<span>2х•(х+6)=14
2x</span>²+12x-14=0
x²+6x-7=0
x²+7x-x-7=0
x(x+7)-(x+7)=0
(x+7)(x-1)=0
x₁=-7
x₂=1
ответ {-7;1}
{y-3x-5=-6
{2x+у=9
{y=3x-1
{2x+3x-1=9
{y=3x-1
{5x=10
{y=3x-1
{x=2
{y=6-1
{x=2
ответ {2;5}
125
* 1,6
------
750
+125
------
200,0
3,14
* 500
----------
1570,00
0,544
* 630
-----------
1632
+ 3254
-----------
341,720