Question

Pomoże mi ktoś z tymi zadaniami ??
a.
{x+y = 5
{x-y=1
b.
{2x+y=4
{-x+y=7
c.
{2x+y=14
{5x+4y=17
d.
{3x+5y=31
{x+2y=12
e.
{3x+5y=31
{x+2y=12
f.
{y+2y=5
{2x-5y=17
g.
{2x-2y=4
{2x+3y=18

Answer 1

A)
{x+y = 5
{x-y=1
-------------
{2x=6
{y=5-x

{x=3
{y=5-3

{x=3
{y=2

b)
{2x+y=4
{-x+y=7 /*2

{2x+y=4
{-2x+2y=14
----------------
{3y=18 /:3
{2x=4-y

{y=6
{2x=4-6 /:2

{y=6
{x=-1

c)
{2x+y=14 /*(-4)
{5x+4y=17

{-8x-4y=-56
{5x+4y=17
-------------------
{-3x=-39 /:(-3)
{4y=17-5x

{x=13
{4y=17-5*13

{x=13
{4y=17-65

{x=13
{4y=-48 /:4

{x=13
{y=-12

d)
{3x+5y=31
{x+2y=12 /*(-3)

{3x+5y=31
{-3x-6y=-36
-----------------
{y=5
{3x=31-5(5)

{y=5
{3x=31-25

{y=5
{3x=6 /:3

{x=2
{y=5


e)to samo co w d)

f) napewno dobrze przepisany przykład ?

g)
{2x-2y=4 /*(-1)
{2x+3y=18

{-2x+2y=-4
{2x+3y=18
----------------
{5y=14 /:5
{2x=18-3y

{y=2⅘
{2x=18-(3*2⅘)

{y=2⅘
{2x=18-8,4

{y=2,8
{2x=9,6 /:2

{x=4,8
{y=2,8