- Thread starter lolily
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What you describe sounds reasonable; so the error will be in the details you left out! Very likely it is just a sign error or something of that sort.

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Here is a start:\(\displaystyle \left\{ \begin{array}{l}3(5a)-4(3a)=a+4\\3d-4(5d)=68\end{array} \right.\)Hello, in my homework I came across this problem:

View attachment 12028

The text didn't really go over how to solve it and I'm finding it difficult to understand. Is there anyone who can explain how to get the answer?

No you have two more equations to setup and then to solve the four.