Equation 1:
2x + y = 25
-Subtract 'y' to both sides (quick note: pretend 'y' is '1')
2x + 1 - 1 = 25 - 1
2x = 24
-Divide '2' to both sides
2x/2 = 24/2
x = 9
Equation 2: 3y - x = 20
-Add 'y' (or 1) to both sides
3y - 1 + 1 = 20 + 1
3y = 21
-Divide '3' to both sides
3y/3 = 21/3
y = 7
irrational number, any real number that cannot be expressed as the quotient of two integers.
Any number that can be written as a fraction with integers is called a rational number . For example, 17 and −34 are rational numbers. (Note that there is more than one way to write the same rational number as a ratio of integers.
1st Is rational
2nd one is irrational
3rd is irrational
4th is rational
Answer:
2
Step-by-step explanation:
log9 (2^-4) = -4.log9 (2)
So this translates to:
5e + 5n = 25.95
2e + 6n = 22.38
One way to solve that is to multiply the top equation by 2, and the bottom equation by 5:
10e + 10n = 51.90
10e + 30n = 111.90
Then subtract the top from the bottom to get:
20n = 60
and divide by 20 to get
n = 3
So you know that note paper costs $3. Substituting that into the top equation you get:
5e + 5*3 = 25.95 or
5e + 15 = 25.95
Subtracting 15 from both sides you get:
5e = 10.95
Dividing by 5 you get:
e = $2.19