Question

sa se afle un numar rational care adunat cu 1 ¾ obtinem triplul sau

Answer 1

x -numarul rational

x + 1 ¾=3x
=> 1 ¾=3x-x
1 ¾=2x
(1×4+3)/4=2x
7/4=2x => x=(7/4):2=7/(4·2)=7/8


Verificare:
7/8 + 1 ¾=7/8 +(1×4+3)/4=7/8 + 7/4=
=7/8 + 14/8 =21/8 (=3× 7/8)

Answer 2

1³/₄=7/4
a=nr rational
a+7/4=3a

aducem la acelasi numitor comun
avem
4a+7=12a
7=12a-4a
7=8a
8a=7
a=7/8

Verificare:
7/8+7/4=21/8
7/8*3=21/8