Question

Rozwiaz rownania i sprawdz swoje rozwiazanie
a) 8x + 5 = 7x b) 7n + 2 = 6n - 3
c) -x + 25 = 2x - 2 d) -9z - 7 = -z - 6
e) 25m - 3 = 24m - 4 f) -s + 15 = 4s - 14
g) 17y + 28 = 19y + 27 h) 8k - 19 = -8k + 19

bardzo pilne na jutro xd pomóżcie koledzy i kolezanki

Answer 1

A) 8x + 5 = 7x
8x-7x=-5
x=-5

spr.
8*(-5)+5=7*(-5)
-40+5=-35
-35=-35
L=P

b) 7n + 2 = 6n - 3
7n-6n=-3-2
n=-5

spr.
7*(-5)+2=6*(-5)-3
-35+2=-30-3
-33=-33
L=P

c) -x + 25 = 2x - 2
-x-2x=-2-25
-3x=-27 /:(-3)
x=9

spr.
-9+25=2*9-2
16=18-2
16=16
L=P

d) -9z - 7 = -z - 6
-9z+z=-6+7
-8z=1 /:(-8)
z=-1/8

spr.
-9*(-1/8)-7=-(-1/8)-6
9/8 -7=1/8 -6
1 ¹/₈ -7=-5 ⁷/₈
-5 ⁷/₈=-5 ⁷/₈
L=P

e) 25m - 3 = 24m - 4
25m-24m=-4+3
m=-1

spr.
25*(-1)-3=24(-1)-4
-25-3=-24-4
-28=-28
L=P

f) -s + 15 = 4s - 14
-s-4s=-14-15
-5s=-29 /:(-5)
s=5,8

spr.
-5,8+15=4*5,8-14
9,2=23,2-14
9,2=9,2
L=P

g) 17y + 28 = 19y + 27
17y-19y=27-28
-2y=-1 /:(-2)
y=½

spr.
17*½ +28=19*½+27
8,5+28=9,5+27
36,5=36,5
L=P

h) 8k - 19 = -8k + 19
8k+8k=19+19
16k=38 /:16
k=2,375

spr.
8*2,375 -19=-8*2,375 +19
19-19=-19+19
0=0
L=P

Answer 2

8x+5=7x
8x-7x=-5
x=-5

7n+2=6n-3
7n-6n=-3-2
n=-5

-x+25=2x-2
-x-2x=-2-25
-3x=-27
x=9

-9z-7=-z-6
-9z+z=-6+7
-8z=1
z=-⅛

25m-3=24m-4
25m-24m=-4+3
m=-1

-s+15=4s-14
-s-4s=-14-15
-5s=-29
s=5 i 4/5

17y+28=19y+27
17y-19y=27-28
-2y=-1
y=½

8k-19=-8k+19
8k+8k=19+19
16k=38
k=2⅜