Can I get an example of systems of equations that represent the solution of this situation below? (It doesn't need to be solved.) Thank you! ^ ^

"1 taco and 1 burrito costs $11. 10 tacos and 5 burritos cost $80. How much is the cost of one burrito?" (x = the cost of a taco, and y = the cost of a burrito)

Rachel is studying the population of a particular bird species in a national park. she observes every 10th bird of that species that she can find in the park. her conclusion is that the birds living in the park who belong to that species generally feed on insects. rachel's sample is . based on the sample she picked, rachel's generalization is