Question

Tak jak w załączniku. Zadanie 4 - a, b, c i d.

Answer 1

4a)
x+y=5
x-2y=-1

 

x=5-y
5-y-2y=-1

x=5-y
-3y=-6 /-3

x=5-y
y=2

 

4b)

y-x=4

3(x+y)=24

 

y=4+x
3x+3y=24

y=4+x
3x+3(4+x)=24

y=4+x
3x+12+3x=24

y=4+x
6x=24-12

y=4+x
6x=12 /6

y=4+x
x=2

y=4+2
x=2

y=6
x=2

 

4c)

x-2y=4
x+3=2y

x=4+2y
4+2y+3=2y

x=4+2y
0y=-7

x=4+2y
y=0

x=4+2*0
y=0

x=4
y=0

 

4d)
3x-1=y-2
4x-3=-2(y-2)

 

y=3x-1+2
4x-3=-2y+4

 

y=3x+1

4x-3=-2(3x+1)+4

 

y=3x+1

4x-3=-6x-2+4

 

y=3x+1

10x=-2+4+3

 

y=3x+1

10x=5 /2

 

y=3x-1
x=1/2

y=3*1/2+1

x=1/2

 

y=1 1/2 +1

x=1/2

 

y=2 1/2

x=1/2