Question

Afla valoarea necunoscutei:

1. 800:[425-13+(48:4)-(89+a×)] =10

2. [(625:a+65×7):5]:3-14=18

3. a×4+(6×7-5×6-72:8)×76=332

4. (651-72×4-306:2):a×9=45

5. 1000-a×[100:(7×12-74)-5]=500

Dau coroana!!! ​

Answer 1

Răspuns:

Eu fac direct rezolvarile nu mai scriu exercitiile!

1)425-13×12-(89+a×4)=80

89+a×4=269-80=>189

a×4=189-89

a=100:4

a=25

2)[(625:a+455):5]:3=18+14

(625:a+455):5=32×3

625:a+455=96×5

625:a=480-455

625:a=25

a=625:25

a=25

3)a×4+(42-30-9)×76=332

a×4+(12-9)×76=332

a×4+3×76=332

a×4+228=332

a×4=332-228

a×4=104

a=104:4

a=26

4)(651-288-153):a×9=45

(363-153):a×9=45

210:a×9=45

210:a=45:9

210:a=5

a=210:5

a=42

5)1000-a×(1000:10-5)=500

1000-a×(10-5)=500

1000-a×5=500

a×5=1000-500

a×5=500

a=500:5

a=100

Explicație pas cu pas:

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