Question

Cine Răspunde pirimul și corect ia coroana

Answer 1

Salut,

a = 1/5+3/7+1/7+4/5+3/7 (aduc la același numitor : 35)
a = 7/35+15/35+5/35+28/35+15/35
a = 22/35+33/35+15/35
a = 55/35+15/35
a = 70/35
a = 2.

b = 3/10-2/9+7/10-7/9 (aduc la același numitor : 90)
b = 27/90-20/9+63/90-70/90
b = 7/90-7/90
b = 0.

a×b = 2×0 = 0.

Succes! :3

Answer 2

( 1/5 + 3/7 + 1/7 + 4/5 + 3/7 ) * ( 3/10 -2/9 + 7/10 - 7/9 ) =
$\frac{7+15+5+28+15}{35}$ * $\frac{27-20+63-70}{90}$ =
70/35 * 0/90 =
70/35 * 0 =
0