x+2x= x+9 3x = x+9 3x-x= 9 2x = 9 x = 4,5 y+(2y-5) a gdzie reszta 3a+4=(a-1)+(a+7) 3a+4=a-1+a+7 3a+4=2a+6 3a-2a=6-4 a=2 (10-2b)+(6-b)=(10-b)+(4-b) 10-2b+6-b=10-b+4-b 16-3b=14-2b 16-14=3b-2b 2=b
a) x+2x=x+9 3x-x=9 2x=9 |:2 x=4,5 b) y+(2y-5) y+2y-5 3y-5 <- to nie jest równanie c) 3a+4=(a-1)+(a+7) 3a+4=a-1+a+7 3a+4=2a+6 a=2 d) (10-2b)+(6-b)=(10-b)+(4-b) 10-2b+6-b=10-b+4-b 16-3b=14-2b 16-14=b b=2 -------------------------------------------------------------------------- b) y+(2y-5)=11-y y+2y-5=11-y 3y-5=11-y 3y+y=11+5 4y=16 |:4 y=4 :)
a x + 2x = x + 9 x + 2x - x = 9 3x = 9 x = 9 : 3 x = 3 b y + (2y - 5) = y + 2y -5 = 3y - 5 c 3a + 4 = (a - 1) + (a + 7) 3a + 4 = a - 1 + a + 7 3a - a - a = - 1 + 7 - 4 a = 2 d (10 - 2b) + (6 - b) = (10 - b) + (4 - b) 10 - 2b + 6 - b = 10 - b + 4 - b - 2b - b + b - b = 10 + 4 - 10 -6 - 3b = - 2 b = - 2 : (-3) b = ⅔
