Пусть х – рублей стоит одна ракетка, а у рублей – один мяч. После скидок стоимость ракетки снизили на 25% , т.е. стоимость ракетки составила 75 % (100%-25%) от х или 0,75х, а стоимость мяча снизилась – 0,90у.
Составим систему уравнений : 8х+10у=4560 8*0,75х+10*0,90у=3780
8х+10у=4560 6x+9y=3780
Решить систему уравнений методом сложения (возьмите систему в скобки {): _8х+10у=4560 [*9 6x+9y=3780 [*10
9(8х+10у)-10(6x+9y)=9*4560-10*3780 72x+90y-60x-90y=41040-37800 12x=3240 х=270 (рублей) – стоит одна ракетки. 8*270+10у=4560 2160+10у=4560 10у=2400 у=240 (рублей) – стоит один мяч ответ: стоимость одно ракетки - 270 рублей, стоимость одного мяча=240 рублей.
There lived an astronomer who was very much involved in his observations.
He often used to look up at the sky at night and start observing the stars.
Once, as he walked looking up at the stars, his leg slipped and he fell into a ditch. He started shouting.
A passer-by, who heard his shouts, helped him out of the ditch and asked, "How did you fall into this ditch?" The astronomer replied, “I was so engrossed in my observations that I did not notice the ditch".
The passer-by asked, "How do you expect to discover things when you fail to take note of things under your nose?" The astronomer walked away with a sad face.
Составим систему уравнений :
8х+10у=4560
8*0,75х+10*0,90у=3780
8х+10у=4560
6x+9y=3780
Решить систему уравнений методом сложения (возьмите систему в скобки {):
_8х+10у=4560 [*9
6x+9y=3780 [*10
9(8х+10у)-10(6x+9y)=9*4560-10*3780
72x+90y-60x-90y=41040-37800
12x=3240
х=270 (рублей) – стоит одна ракетки.
8*270+10у=4560
2160+10у=4560
10у=2400
у=240 (рублей) – стоит один мяч
ответ: стоимость одно ракетки - 270 рублей, стоимость одного мяча=240 рублей.
There lived an astronomer who was very much involved in his observations.
He often used to look up at the sky at night and start observing the stars.
Once, as he walked looking up at the stars, his leg slipped and he fell into a ditch. He started shouting.
A passer-by, who heard his shouts, helped him out of the ditch and asked, "How did you fall into this ditch?" The astronomer replied, “I was so engrossed in my observations that I did not notice the ditch".
The passer-by asked, "How do you expect to discover things when you fail to take note of things under your nose?" The astronomer walked away with a sad face.
Пошаговое объяснение:
думаю правильно