Question

o ograda are oi si gaini nr capetelor in total e de 27 iar al picioarelor 78. cate gaini si cate oi sunt ?

Answer 1

o+g=27=>o=27-g
4o+2g=78
4(27-g)+2g=78
108-4g+2g=78
2g=30
g=15
o=12

Answer 2

o+g=27         g=27-o
4o+2g=78
4o+2(27-o)=78
4o+54-2o=78
2o=78-54
o=24:2
o=12 oi
g=27-12=15
g=15 gaini