Question

Afla nr necunoscut din egalitati :a)100+x:5=107;b)x×7_19=51;c)19_(x+5)×2=7;d)60:(x_97)=523;e) 10×[10+(10+x)×10]+10=1210 f)430-[5×(11-2x)+18]×10=100.

Answer 1

a)  

100 + x : 5 = 107

x : 5 = 107 - 100

x : 5 = 7

x = 7 × 5

x = 35

Verific :    100 + 35 : 5 = 100 + 7 = 107

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b)

X ×7 - 19 = 51

7 X = 51 + 19

7 X = 70

X = 70 : 7

X = 10

Verific  10 × 7 - 19 = 70 - 19 = 51

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c)

19 - ( x + 5 ) × 2 = 7

( x + 5 ) × 2 = 19 - 7

( x + 5 ) × 2 = 12

x + 5 = 12 : 2

x + 5 = 6

x = 6 - 5

x = 1

Verific:  19 - ( 1 + 5 ) × 2 = 19 - 12 = 7

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d)

60 : ( x - 97) = 523 → 60 < 523 ( deimpartitul < catul ) ⇔ exercitiul postat de tine este gresit

60 : ( x - 97 ) = 5

x - 97 = 60 : 5

x - 97 = 12

x = 12 + 97

x = 109

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e)

10 × [ 10 + ( 10 + x ) × 10 ] + 10 = 1 210

10 × [ 10 + ( 10 + x ) × 10 ] = 1 210 - 10

10 × [ 10 + ( 10 + x ) × 10 ] = 1 200

10 + ( 10 + x ) × 10 = 1 200 : 10

10 + ( 10 + x ) × 10 = 120

( 10 + x ) × 10 = 120 - 10

( 10 + x ) × 10 = 110

10 + x = 110 : 10

10 + x = 11

x = 11 - 10

x = 1

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f)

430 - [ 5 × ( 11 - 2 x ) + 18 ] × 10 = 100

[ 5 × ( 11 - 2 x ) + 18 ] × 10 = 430 - 100

[ 5 × ( 11 - 2 x ) + 18 ] × 10 =  330

5 × ( 11 - 2 x ) + 18 = 330 : 10

5 × ( 11 - 2 x ) + 18 = 33

5 × ( 11 - 2 x ) = 33 - 18

5 × ( 11 - 2 x ) = 15

11 - 2 x = 15 : 5

11 - 2 x = 3

2 x = 11 - 3

2 x = 8

x = 8 : 2

x = 4

Answer 2

a) x:5=107-100

x:5=7

x=7*5

x=35

b) x*7=51+19

x*7=70

x=70:7

x=10

c) (x+5)*2=19-7

(x+5)*2=12

x+5=12:2

x+5=6

x=6-5

x=1

d) nu cred ca ai scris bine aici

e) 10*[10+(10+x)*10]=1210-10

10*[10+(10+x)*10]=1200

10+(10+x)*10=1200:10

10+(10+x)*10=120

(10+x)*10=120-10

(10+x)*10=110

10+x=110:10

10+x=11

x=11-10

x=1

f) 430-[5*(11-2x)+18]=100:10

430-[5*(11-2x)+18=10

5*(11+2x)+18=430-10

5*(11+2x)+18=420

(11+2x)+18=420:5

(11+2x)+18=84

11+2x=84-18

11+2x=62

2x=62-11

2x=51

x=51/2