Question

A) W klamerce dwa przykłady:
3x+2y=2
3x+y=1
b) W klamerce dwa przykłady:
5x+10y=5
3y=2x=12
c) W klamerce dwa przykłady:
2y-x=8
4x+3y=1
To jest zadanie z 2 klasy gimnazjum

Answer 1

A)
{3x + 2y = 2 /*(-1)
{3x + y = 1

{-3x - 2y = -2
(3x + y = 1
--------------- +
-y = -1/*(-1)
y = 1
3x + 1  = 1
3x = 0/:3
x = 0

{x = 0
{y = 1


b)
{5x + 10y = 5
{3y + 2x = 12

{5x +10y = 5/*2
{2x + 3y = 12/*(-5)

{10x + 20y = 10
{-10x - 15y = -60
-------------------- +
5y = -50/:5
y = -10
5x + 10*(-10) = 5
5x - 50 = 5
5x = 55 /:5
x = 11

{x = 11
{y = -10

c)
{2y - x = 8
{4x + 3y = 1

{-x + 2y = 8 /*4
{4x + 3y = 1

{-4x + 8y = 32
{4x + 3y = 1
------------------- +
11y = 33 /:11
y = 3
-x + 2*3 = 8
-x + 6 = 8
-x = 2 /*(-1)
x = -2

{x = -2
{y = 3