6,7*(7,9-y)=28,81 9,14z-(3,78z+2,87z)=12,45

Question

6,7*(7,9-y)=28,81
9,14z-(3,78z+2,87z)=12,45

Answer 1

3.78z+2.87z=6.65z
9.14z-6.65z=2.49z
2.49z=12.45
Z=12.45:2.49
z= 5

Comments

Вот второе решение:(7.9-у)=28.81:6.7

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(7.9-у)=4.3 у=4.3+7.9 у=12.2