Question

3+7×[45-3×(4×a+3)]=3. Va rog frumos să mă ajutați la acest exercițiu

Answer 1

Răspuns:

Explicație pas cu pas:

3 + 7 × [ 45 - 3 × ( 4 × a + 3 ) ] = 3

7 × [ 45 - 3 × ( 4 × a + 3 ) ] = 3 - 3

45 - 3 × ( 4 × a + 3 ) = 0 : 7

3 × ( 4 × a + 3 ) = 45 - 0

3 × ( 4 × a + 3 ) = 45

4 × a + 3 = 45 : 3

4 × a + 3 = 15

4 × a = 15 - 3

4 × a = 12

a = 12 : 4

a = 3 → numarul, aflat prin metoda mersului invers

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Verific:  

3 + 7 × [45 - 3 × ( 4 × 3 + 3 ) ] = 3

= 3 + 7 × ( 45 - 3 × 15 ) =

= 3 + 7 × 0 =

= 3 + 0 =

= 3

Answer 2

3+7x[45-3x(4a+3)]=3

3+7x(45-12a-9)=3

3+7x(36-12a)=3

3+252-84a=3

255-84a=3

-84a=3-255

-84a=-252/x(-1)

84a=252

a=252:84

a=3