Question

zad 11 str 199 Matematyka z plusem klasa 1 gimnazjum

a)

2x + 3 2 - x

______ = _____ - x

5 3

b)

x - 1 x - 1 1

_____ - ________ = ____

2 3 4

c)

4x + 7 5x - 1

_____ - _______ = x + 5

2 6

d)

x + 5 2x + 1 1

_____ - _______ = ___ (2 - x)

4 8 2

P.S. TO SĄ UŁAMKI!!!

Answer 1

a)

2x + 3        2 - x

______  =  _____  - x  / *15

5                     3

 

6x+9=10-5x-15x

6x+5x+15x = 10-9

26x=1 / :26

x = 1/26

B)

x - 1           x - 1            1

_____  -  ________  =  ____     / *12

2                    3             4

6x+6-4x+4 = 3

2x = 3-6-4

2x = -7 / 2

x = -7/2

x = -3,5

 

c)

4x + 7       5x - 1

_____  -  _______ = x + 5   / *6

2                    6

 

12x+21 - 5x+1=6x+30

12x-5x-6x= 30-1-21

x = 8

 

d)

x + 5        2x + 1           1

_____  -  _______  =  ___ (2 - x)   / *8

4                  8             2

 

2x+10-2x-1 = 4(2-x)

2x+10-2x-1 = 8-4x

2x-2x+4x = 8+1-10

4x = -1 / 4

x = -1/4