the mass of 3 dictionaries and 2 textbook is 8 kg and the mass of 3 dictionaries and 3 textbook is 9 kg. find the mass of 5 textbooks?

3 answers

3d + 3t = 9

3d + 2t = 8

Subtract second equation from first, then multiply by 5.
We do like this3+3 3+2 9-8 1multiply by 5
We do like this3+3 3+2 9-8 1multiply by 5