Thework in the library but there was was great!
2
1. Did
remember to water the plants yesterday?
3.
2. Did you do
special at the weekend?
cleaned the classroom after the party yesterday.
It was a mess.
4. I'm bored. I have
interesting to do.
5. My mum never cleans the house alone.
always
helps her.
6. Come here! There's
I'd like to discuss with you.
3
a) Read the text and answer the questions.
anywhere / nowhere / somewhere to sit and I had to go
anywhere / nowhere / somewhere else.
10. I enjoyed the party yesterday. Everything / nothing / nobody
Complete the gaps. Use something, somebody, anything,
anybody, nothing, nobody.
They look a bit dry.
Решаем уравнение в целых числах:
(2х-у)(2х+у)=3
Слева произведение двух целых чисел (2х-у) и (2х+у) и справа 1 и 3 или (-1) и (-3)
Перебором устанавливаем, что возможны следующие варианты:
Решаем каждую сложения.
Из первой системы 4х=4, х=1, тогда y=3-2x=3-2=1 ответ (1;1)
Из второй 4х=4, х=1, тогда y=1-2x=1-2=-1 ответ (1:-1)
Из третьей 4х=-4, х=-1, тогда у = -3-2х=-3-2(-1)=-1 ответ (-1:-1)
Из четвертой 4х=-4, х=-1, тогда у=-1-2х=-1+2=1 ответ (-1;1)
ответ. (1;1) (1;-1) (-1;-1) (-1;1)