X and y are the numbers
y>x
sum (addition) of twice a number (2x) and larger number (y) is (=) 145
2x+y=145
difference between them is 55 (y is bigger so it would be x is subtracted from y)
y-x=55
so the equations are
2x+y=145 and
y-x=55
we could add x to both sides in the 2nd equation to obtain
y=x+55, but that doesn't really represent that the difference is 55, though they are the same euation
so I would say C and D only
In the metric system, you give a name to the following multiples: 10, 100, 1000, 0.1, 0.01, 0.001, and then you skip three places. So, you have

And thus 0.000001 of something is a micro-something (i.e. one millionth of a certain unit)
Sorry we can’t help with this
He bought 3 small notebooks (3*7=21) and 3 large notebooks (3*10=30)
21+30=51
Step-by-step explanation:
Given function is y = –x.
Substitute the values of x in the function and find the values of y.
y = –x
At x = –2,
y = –(–2) = 2
At x = –1,
y = –(–1) = 1
At x = 0,
y = –(0) = 0
At x = 1,
y = –1(1) = –1
At x = 2,
y = –(2) = –2
Now, substitute the values of y in the table.
The image of the table is attached below.