### Question Description

algebraically determine solution for linear system

1. 3c + 7d =3

2. 5c - 4d = -42

## Final Answer

Thank you for the opportunity to help you with your question!

1. we know c=(3-7d)/3

plug c=(3-7d)/3 into 5c-4d=-42 we get

5(3-7d)/3-4d=-42, 15-35d-12d=-126, -47d=-141, d=3

thus d=3, c=(3-21)/3=-6

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