Question

VA ROG REPEDE DAU COROANA SI 50 DE PUNCTE

Answer 1

Notezi suma de bani initiala cu x
I. x-2/6·x+16=
x-1/3·x+16=
x-x/3+16=
Amplifici x si 16 cu 3
3x/3-x/3+48/3=(3x-x+48)/3=
(2x+48)/3 a cheltuit in prima zi
Rest: x-(2x+48)/3=
Amplifici x cu 3
[3x/x-(2x+48)]/3=
(3x-2x-48)/3=
=(x-48)/3

II.[(x-48)/3]/4+12=
(x-48)/3·1/4+12=
(x-48)/12+12=
(x-48)/12+144/12=
(x-48+144)/12=
(x+96)/12 a cheltuit in a doua zi
Rest: (x-48)/3-(x+96)/12=
x/3-16-x/12-8=
Amplifici prima fractie cu 4
4x/12-x/12-24=
3x/12-24=
x/4-24=
x/4-96/4=
=(x-96)/4

III.(x-96)/4·3/5+15=
3(x-96)/20+15=
3(x-96)/20+300/20=
[3(x-96)+300]/20 a cheltuit in a treia zi
Rest: (x-96)/4-[3(x-96)+300]/20=
Amplifici prima fractie cu 5
5(x-96)/20-[3(x-96)+300]/20=
=[2(x-96)-300]/20
Simplifici cu 2 si iti ramane [(x-96)-150]/10

[(x-96)-150]/10=45
(x-96)-150=45·10
(x-96)-150=450
x-96=600
x=696 lei 

In prima zi a cheltuit (2·696+48)/3=1440/3=480 lei
In a doua zi a cheltuit (696+96)/12=792/12=66 lei
In a treia zi a cheltuit [(696-96)-150]/10=(600-150)/10=450/10=45 lei