During a hike, Vijay saw a total of 19 birds and butterflies. Knowing that birds have 2 wings and butterflies have 4 wings, he counted 52 wings. Use a model to determine how many birds he saw.

Question

anonymous · Answer

choices:
 9 

 10 

 11 

 12

diyadiya · Answer

let the number of birds be x and Butterflies be y

x + y = 19  ( since he saw a total of 19 of them)

Birds have 2 wings & butterflies have 4 wings 
we can say that 2 times Number of Birds plus 4 times number of Butterflies is equal to 52

2x + 4y = 52
Now we have two equations

x+y=19
2x+4y = 52

can you solve these two equations?

anonymous · Answer

Let the birds be x and butterflies be y.
then , x+y=19   , y=19-x

and , 2x+4y=52

2x+4(19-x)=52
2x+76-4x=50
-2x=50-76
-2x=-26
x=-26/-2
x=13, birds=13