Question

19. Află numărul necunoscut:
a) 2. (x+3,9) +1,2 = 20
b) 4. (x + 2,05) -5,7 = 13,8
c) 2. (x+1)+3,4 = 5,98
d) 3. (x+2,1) + X+0,8 = 17,3
e) 18+2.(2x+0,6)-14,5=21 f)5x+3,18 = 30
g) 5.(3.14+x) - 11 = 8,71
h) 5.(3,4+2x) - 12,3 = 10
i) 2.(4 + 3x)-1,4 = 18,9​

Answer 1

Răspuns:

a. 2×+7,8+1,2=20

2×+9=20

2×=11

×=5,5

b.3×+6,3+×+0,8=17,3

4×+7,1=17,3

4×=10,2

×=2,55

g.15,60+5×-11=8,71

15,60+5×=19,71

5×=19,71-15,60

5×=4,11

×=4,11:5

×=0,82