Question

Zad. 1. Uprość wyrażenia:
a) 3b + 4a + 3 + 2a – 5b – 6
b) 10x+ y – 5 – x +5 – y
c) k + 3g – 6 + 4k – g
Zad.2. Oblicz wartości wyrażeń dla x = -2 i x = 3
a) -3x + 4 =
b) -2(x – 3) + 9=
c) 5(1-x) -4 =
Zad. 3. Rozwiąż równania:
a) 3x + 13 = -2x – 3
b) 4( -x – 4) = 32 – x
c) 12 – 4x = x – 4
d) = 3x
e) = 18
f) = 13
g) 17x + 4 = 3x

Answer 1

1.
a. -2b+6a-3
b. 9x
c. 5k+2g-6
2. dla -2
-3*-2+4=6+4=10
-2(-2-3)+9=-2*-5+9=10+9=19
5(1--2)-4=5*3-4=15-4=11
dla 3
-3*3+4=-9+4=-5
-2(3-3)+9=-2*0+9=0+9=9
5(1-3)-4=5*-2-4=-10-4=-14
3,
a. 3x+13 = -2x-3 /+2x
5x+13 = -3 /-13
5x = -16 //5
x= 3 i 1/5
b. 4(-x-4) = 32-x
-4x-16 = 32-x /+x
-3x-16 = 32 /+16
-3x = 38 //-3
x = 12 i 2/3
c. 12-4x = x-4 /+4
16-4x=x /+4x
16 = 5x
3 i 1/5 = x

Answer 2

Zad1.
a)
3b + 4a + 3 + 2a – 5b – 6=

=4a + 2a + 3b - 5b + 3 - 6=

=6a - 2b - 3


b)
10x+ y – 5 – x +5 – y =

= 10x - x + y - y - 5 + 5=

= 9x



c)
k + 3g – 6 + 4k – g =

= 3g - g + k + 4k - 6=

= 2g + 5k - 6



Zad.2.

a)
dla x= -2

-3x + 4 =

= -3*(-2) + 4=

= 6 + 4=

= 10


dla x = 3

-3x + 4=

= - 3 * 3 + 4=

= - 9 + 4=

= - 5



b)
dla x= - 2

-2(x – 3) + 9=

= -2(-2-3)+ 9 =

= - 2(-5) + 9 =

= 10 + 9 =

= 19



dla x= 3

-2(x – 3) + 9=

= -2(3-3) + 9=

= -2*0 + 9=

= 0 + 9 =

= 9



c)
dla x= - 2


5(1-x) -4 = 

= 5(1 - (-2)) - 4=

= 5(1 + 2) - 4=

= 5*3 - 4=

= 15 - 4=

= 11



dla x= 3

5(1-x) -4 = 

= 5(1 - 3) - 4=

= 5*(-2) - 4 =

= - 10 - 4=

= - 14


Zad. 3. 
a)
3x + 13 = -2x – 3

3x + 2x = - 3 - 13

5x = - 16

x= - 16 : 5

x= - 3,2

spr.
3x + 13 = -2x – 3

L = 3x + 13= 3*(-3,2) + 13= - 9,6 + 13 =  3,4

P = -2x - 3= - 2*(-3,2) - 3= 6,4 - 3= 3,4

L=P



b)
4( -x – 4) = 32 – x

-4x - 16 = 32 -x

-4x + x= 32 + 16

-3x= 48

x= 48 : (-3)

x= - 16

spr.
4( -x – 4) = 32 – x

L = 4(-x - 4) = 4(-(-16) - 4) = 4(16 - 4) = 4 * 12= 48

P = 32 - x= 32 - (-16) = 32 + 16 = 48

L=P



c)
12 – 4x = x – 4

-4x - x= - 4 - 12

-5x = - 16

x= -16 : (-5)

x= 3,2

spr.
12 – 4x = x – 4 
L = 12 - 4x= 12 - 4 * 3,2= 12 - 12,8 = - 0,8

P = x- 4= 3,2 - 4= - 0,8

L=P



g)
17x + 4 = 3x

17x - 3x = - 4

14x= - 4

x= - 4 : 14

x= - 4/14

x = - 2/7


spr.

17x + 4 = 3x

L = 17x + 4= 17 * ( - 2/7) + 4= - 34/7 + 4= - 4 i 6/7 + 4= - 6/7

P = 3x= 3 * (-2/7) = - 6/7

L = P