Question

am nevoie urgennntttt dau coroana​

Answer 1

Răspuns:

a·b=490

2a=5b=k=>a=k/2,b=k/5

k/2·k/5=490

k²/10=490

k²=490·10=>k=√4900=>k=70

a=70/2=35

b=70/5=14

_______________

5a=7b=k=>a=k/5,b=k/7

(a+b)/2=24=>a+b=24·2=>a+b=48

k/5+k/7=48

7k+5k=1680

k=1680:12

k=140

a=140/5=28

b=140/7=20

Answer 2

Răspuns:

4.a×2=b×5=k

a=k/2

b=k/5

a×b=490 => k/2×k/5=490

k²/10=490

k²=4900 => k²=70² => k=70

a=70:2=35

b=70:5=14

Verific:

35×14=490 => (corect)

5.(a+b)/2=24

a+b=48

a×5=b×7=k

a=k/5

b=k/7

k/5×k/7=48

7k/35+5k/35=12k/35=48

k=35×48/12=140

a=140:5=28

b=140:7=20

Verific:

28+20=48 => (corect)