What effect would the disappearance of krill have on whale populations

If the population of krill decreases, the abundance of krill could influence future whale populations in the Southern Hemisphere such as Blue, Southern Right and Fin whales, according to new research from CSIRO, Australia’s national science agency, and the University of Queensland Krill is the main food source for whale, because krill is the main food source for whale

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4

what

explanation: