Can someone explain how to do this please?

Mathematics

1 answer:

Jobisdone [24]3 years ago

4 0

$\bf \begin{cases} \boxed{y}=-2x\\\\ -x-y=4 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{since we know what \boxed{y} is, let's substitute it in the 2nd equation}}{-x-\left( \boxed{-2x} \right)=4\implies -x+2x=4\implies x=4} \\\\[-0.35em] ~\dotfill\\\\ y=-2x\implies y=-2(4)\implies y=-8 \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill (4,-8)~\hfill$

You might be interested in

Out of these numbers which of them differ by 46. 29,17,38,71,35,63,24

mafiozo [28]

Answer:

Step-by-step explanation:

Add 46 to each number, see if the sum is in the list. In the set of 7 numbers listed, two of them are even (24 and 38), and the other 5 numbers are odd

We do not need to look at all differences.

We need to find two numbers fairly far appart,

and not all look promising.

You could look at approximate differences,

or you could look at the last digit.

71-35 and 63-17 are the only promising differences,

because 71 and 63 are the only numbers large enough to be 46 more than another number in that list,

and when you calculate the last digit you calculate

11-5=6 and 13-7=6.

71-35=36

4 0

3 years ago

An oil refinery is located on the north bank of a straight river that is 2 km wide. A pipeline is to be constructed from the ref

VLD [36.1K]

Answer

The answer and procedures of the exercise are attached in the following archives.

Step-by-step explanation:

You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.