Sand lays in two piles, and in the first pile - вопрос №155253823 от mrden3333 10.10.2021 00:06

Question

Алгебра: Sand lays in two piles, and in the first pile there is 3 times more sand than in the second. After 20 tons of sand was taken from the first pile, and 10 tons were brought inthe second, in both piles the amount of sand became equal. How many tons of sandwere in the two piles initially?​

mrden3333 · Answer

Пусть х(м) ткани ушло на одно платье
у(м) ткани ушло на один сарафан,
зная, что на одно платье и три сарафана ушло 9м ткани , составим первое уравнение системы: х+3у=9
зная, что на три платья и пять таких же сарафанов ушло 19 м ткани составим второе уравнение системы: 3х+5у=19
СОСТАВИМ СИСТЕМУ:
х+3у=9,
3х+5у=19 умножим первое уравнение системы на)-3) , получим:-3х-9у=-27
-3х-9у=-27,
3х+5у=19
Сложим первое уравнение со вторым: -4у=-8,у=-8:(-4),у=2
подставим у=2 в уравнение: х+3у=9, х+3*2=9,х+6=9,х=9-6,х=3
х=3(м)-ушло на одно платье,
у=2(м)-ушло на один сарафан.
ответ: 3м, 2м.

Sand lays in two piles, and in the first pile there is 3 times more sand than in the second. After 20 tons of sand was taken from the first pile, and 10 tons were brought inthe second, in both piles the amount of sand became equal. How many tons of sandwere in the two piles initially?​

Sand lays in two piles, and in the first pile there is 3 times more sand than in the second. After 20 tons of sand was taken from the first pile, and 10 tons were brought in

the second, in both piles the amount of sand became equal. How many tons of sand

were in the two piles initially?