URGENT!!! aflati termenul necunoscut (adica x) din relatiile
a. (( x-5) x 2 + 14) :2 + 1 =21
b. (((x+3):4)+8) x 5 - 12 =38
c. 20 : ((3 x (x-6) + 20) : 8) + 5 =10
d. 10 - ( 29 + ((3 ₓ x + 4) - 5) :5 - 8) : 11 =8

Question

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Icecon2005 Icecon2005 · Answer 1 · 2018-09-20T12:21:09+03:00

a.

(( x-5) × 2 + 14) :2 + 1 =21

(( x-5) × 2 + 14) :2 = 21 - 1

(( x-5) × 2 + 14) = 20 × 2

2x - 10 + 14 = 40⇒2x = 40 - 4⇒ 2x = 36

⇒ x = 18

b)

(((x+3):4)+8) × 5 - 12 =38

(((x+3):4)+8) × 5 = 38 + 12

(((x+3):4)+8) = 50 : 5

(((x+3):4)+8) = 10

(x + 3 ) + 8 × 4 = 10 × 4

x + 3 = 40 - 32⇒ x + 3 = 8 ⇒ x = 8 - 3

⇒ x = 5

c.

20 : ((3 × (x-6) + 20) : 8) + 5 = 10

20 : ((3 × (x-6) + 20) : 8) = 10 - 5

c. 20 : ((3 × (x-6) + 20) : 8) = 5

20 × 8 = 5 × (3 × (x-6) + 20)

160 = 5 ( 3x - 18 +20)⇒160 = 15x +10⇒150 = 15x⇒ x =150 :15

x = 10

d.

10 - ( 29 + ((3 x + 4) - 5) :5 - 8) : 11 =8

10 - 8 = ( 29 + ((3 x + 4) - 5) :5 - 8) : 11

2 = (29 + (3x -1) / 5 - 8) : 11

2 = [29 + (3x -1-40)/5]:11

2=(104 + 3x)/5 × 1/11⇒2 × 5 × 11 = 104 + 3x⇒110 - 104 = 3x

6 = 3x ⇒ x = 6 : 3

⇒ x = 2