Odpowiedź:
Zadanie 4
a)
x + 2x = x + 9
3x = x + 9
3x - x = 9
2x = 9 /: 2
x = 4,5
b)
y + 2y - 5 = 11 - y
3y - 5 = 11 - y
3y + y = 11 + 5
4y = 16 /: 4
y = 4
c)
3a + 4 = a - 1 + a + 7
3a + 4 = 2a + 6
3a - 2a = 6 - 4
a = 2
d)
10 - 2b + 6 - b = 10 - b + 4 - b
16 - 3b = 14 - 2b
-3b + 2b = 14 - 16
-b = -2 /: (-1)
b = 2
a) x+2x=x+9
x+2x-x=9
2x=9/2
x=4,5
b) y+2y-5=11-y
y+2y+y=11+5
4y=16/4
y=4
c) 3a+4=a-1+a+7
3a-a-a=-1+7-4
a=2
d) 10-2b+6-b=10-b+4-b
-2b-b+b+b=10+4-10-6
-b=-2/-1
b=2
