Question

Afla numarul necunoscut din expresiile:A) (a+27:3)x5=95; B)2+bx9-25=40; C) (c-104+2)x5+3=98; D) (dx4+20):4=12

Answer 1

a=10(10+9=19*5=95)
b=7(2+7*9-25=65-25=40)
c=121(121-104+2=19*5=95+3=98)
d=7(7*4+20=48:4=12)

Answer 2

a) (a + 27 : 3) × 5 = 95
(a + 9) × 5 = 95
5a + 45 = 95/-45
5a = 50/:5
a = 10

b) 2 + b × 9 - 25 = 40
2 + 9b - 25 = 40/+25
2 + 9b = 65/- 2
9b = 63/:9
b = 7

c) (c - 104 + 2) × 5 + 3 = 98
( c - 102) × 5 + 3 = 98/ - 3
5c - 510 + 3 = 98/ - 3
5c - 510 = 95/ + 510
5c = 605/: 5
c = 121

d) ( d × 4 + 20) : 4 = 12/ × 4
(d × 24) = 12 × 1/4
d × 24 = 3/:24
d = 3 × 1/24
d = 1/6