Răspuns :
A+B =78
2A/5 =B/A ; B =4*2A/5 =8A/5
A + 8A/5 =78 (numitor 5)
5A+8A =390
13A =390
A =30
B =8A/5 =8*30 /5 =48
2A/5 =B/A ; B =4*2A/5 =8A/5
A + 8A/5 =78 (numitor 5)
5A+8A =390
13A =390
A =30
B =8A/5 =8*30 /5 =48
a +b= 78
2a/5 = b /4 ⇒ b= (2ax4) / 5 ⇒ b= 8a/5
a+ 8a/5 = 78
aducem la acelasi numitor
5a+8a= 390
13a=390
a= 30
b=( 8x30) /5
b=48
V: a+b= 30+48= 78 (adevarat)
2a/5 = b /4 ⇒ b= (2ax4) / 5 ⇒ b= 8a/5
a+ 8a/5 = 78
aducem la acelasi numitor
5a+8a= 390
13a=390
a= 30
b=( 8x30) /5
b=48
V: a+b= 30+48= 78 (adevarat)