SOLUTION: The Mackenzie River is 1183 km longer than the St Lawrence River. The sum of their lengths is 7299 km. How long is each river?

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Question 1137768: The Mackenzie River is 1183 km longer than the St Lawrence River. The sum of their lengths is 7299 km. How long is each river?

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

let the Mackenzie River length be L and the St Lawrence River length be L%5B1%5D
The Mackenzie River is 1183km longer than the St Lawrence River.
L=L%5B1%5D%2B1183km....eq.1
The sum of their lengths is 7299km

L%2BL%5B1%5D=7299km........substitute L from eq.1
L%5B1%5D%2B1183km%2BL%5B1%5D=7299km
2L%5B1%5D=7299km-1183km
2L%5B1%5D=6116km
L%5B1%5D=6116km%2F2
L%5B1%5D=3058km

now go to eq.1

L=L%5B1%5D%2B1183km....eq.1, substitute L%5B1%5D
L=3058km%2B1183km
L=4241km

so, the Mackenzie River is 4241km long, and the St Lawrence River is 3058km long