david and joseph have a total of 328 marbles. Mathew and david have 176 marbles. joseph has 5 times as many as Mathew. how many marbles does david have?

2 answers

d + j = 328

m+d = 176

j = 5m

put j = 5m into the first to find d
then put d into the second to find m
Now you know everybody's marbles
I don't get it