Question

Determinați numărul a pentru care
10 ∙ {10 + 10 ∙ [0,3 + 0,3 ∙ (3,3 ‒ a )]} = 220.

Cine vrea coronița? :))

Answer 1

10 × { 10 + 10 × [ 0, 3 + 0, 3 × ( 3, 3 - a ) ] } = 220

10 + 10 × [ 0, 3 + 0, 3 × ( 3, 3 - a ) ] = 220 : 10

10 + 10 × [ 0, 3 + 0, 3 × ( 3, 3 - a ) ] = 22

10 × [ 0, 3 + 0, 3 × ( 3, 3 - a ) ] = 22 - 10

10 × [ 0, 3 + 0, 3 × ( 3, 3 - a ) ] = 12

0, 3 + 0, 3 × ( 3, 3 - a ) = 12 : 10

0, 3 + 0, 3 × ( 3, 3 - a ) = 1, 2

0, 3 × ( 3, 3 - a ) = 1, 2 - 0, 3

0, 3 × ( 3, 3 - a ) = 0, 9

3, 3 - a = 0, 9 : 0, 3

3, 3 - a = 3

a = 3, 3 - 3

a = 0, 3