Let's say each row has x desks and there are y rows.

We then know that x*y =25

We also know that x*2-5=y (number number of rows is five less than twice the number of desks in each row)

So we substitute: x*(x*2-5)=25
putting numbers out of the brackets:
2x*x-5x=25

2x*x-5x-25=0

(2x+5)(x-5)=0 (this bracketing is true: you can check it by expanding it:
2x*x-10x+5x-25

So that means that either x=-2.5which can't be : there can't be a fractional number of benches,

or x=5
so each row has 5 desks and there are 2*5-5 rows, or 5 rows.

6 0

3 years ago

Match the numbers in standard notation with the corresponding numbers in scientific notation.

ankoles [38]

Answer:

a) 864,000,000,000 8.64E11

b) 8,640,000,000 8.64E9

c) 86,400,000,000,000 8.64E13

d) 864,000,000,000,000 8.64E14

Step-by-step explanation:

A scientific notation is a way to represent very large values into the decimal form.

Steps to write in scientific notation:

Move the decimal to left before first digit of the given number.

Find the number of times decimal is moved to left.

Put that number in the exponent of e.

So, matching:

a) 864,000,000,000 8.64E11

b) 8,640,000,000 8.64E9

c) 86,400,000,000,000 8.64E13

d) 864,000,000,000,000 8.64E14

8 0

3 years ago

I forgot how I check to see if my answer is right :,) can anyone help me ;v; The answer is right I just forgot how to check it

Novosadov [1.4K]

Answer:

see below

Step-by-step explanation:

To check your solution , plug the value of k into the original equation

6(7k-10) =24

k=2

6(7*2-10) =24

6(14-10) =24

6(4) =24

24=24

The solution is correct

3 0

2 years ago