Odpowiedzi

2010-02-15T20:34:17+01:00
1) {-2y=-1
{y-4,5=-3x

{y=0,5
{0,5-4,5=-3x

{y=0,5
{ -4=-3x

{y=0,5
{ 0,75=x


2) {4a-7b=-19
{3a+2b=22 /*3,5

{4a-7b=-19
{10,5a+7b=77
+___________________
14,5a = 58
a= 4

{12 + 2b = 22

{ 2b= 10

{b = 5

3) {2x+y= 2 /*-2
{4x+2y=4


{-4x - 2y = -4
{ 4x +2y = 4
+______________
0= 0
2010-02-15T20:35:07+01:00
{6-2y=5 : 2
{3x+y-4,5=0

{3-y=2,5
{3x+y=4,5 y się skracają

{3x = 3 :3
x=1


{4a-7b=-19 *3
{3a+2b=22 *(-4)

{12a-21b=-57
{-12a-8b=-88
-29b=-145 :29
b=5

{2x+y=2 * (-2)
{4x+2y=4

{-4x-2y=-4
{4x+2y=4

0=0

2010-02-15T20:41:57+01:00
6-2y=5
3x+y-4,5=0/+4,5
6-2y=5/-6
3x+y=4,5
-2y=-1/:1
3x+y=4,5/-3x
2y=1
y=4,5-3x
2y=1
y=4,5-3x
2(4,5-3x)=1
y=4,5-3x
9-6x=1/-9
y=4,5-3x
-6x=-8/:-6
y=4,5-3x
x=1,3
y=4,5-3*1,3
x=1,3
y=4,5-3,9
x=1,3
y=0,6

2) {4a-7b=-19
{3a+2b=22 /*3,5

{4a-7b=-19
{10,5a+7b=77
+___________________
14,5a = 58
a= 4

{12 + 2b = 22

{ 2b= 10

{b = 5

3) {2x+y= 2 /*-2
{4x+2y=4


{-4x - 2y = -4
{ 4x +2y = 4
+______________
0= 0