Answer:
each notebook costs $2.70
each pack of pencils costs $1.50
Step-by-step explanation:
system of equations:
let p = pack of pencils
let n = notebook
3p + 5n = 18
4p + 4n = 16.8
I used the elimination method by multiplying the first equation by 4 and the second equation by -3
4(3p + 5n = 18) = 12p + 20n = 72
-3(4p + 4n = 16.8) = -12p -12n = -50.4
adding the new equations together you get: 8n = 21.6
n = 21.6/8
n = $2.70
solve for 'p':
3p + 5(2.7) = 18
3p + 13.5 = 18
3p = 4.5
p = $1.50
900 divided by 3 is 300 so 300 students bring their lunch opposed to 600 students who do not.
Answer:
2x + 10
Step-by-step explanation:
To expand (using the distributive property) <u>multiply</u> the number outside the bracket i.e. in this case '2', with the <u>values inside the brackets</u>.
So multiply '2' and 'x' and '2' and 5' and add or subtract on basis of whether the second value is positive or negative.
So
2(x + 5)
= (2*x)+(2*5)
=2x+10
<em>extention note:</em> <u>be careful</u> when the symbol within the equation within the brackets is a subtraction because it implies that the second value would instead be a negative number and should be treated as such.
an example
2(x-5)
= (2*x)+(2*-5)
=2x -10
Anyhow, I hope this helped!
2/3x - 1/2 = 1/3 + 5/6x....multiply the entire equation by the common denominator of 6...this will get rid of the fractions.
6(2/3x - 1/2) = 6(1/3 + 5/6x) =
4x - 3 = 2 + 5x...subtract 5x from both sides
4x - 5x - 3 = 2...add 3 to both sides
4x - 5x = 2 + 3...combine terms
-x = 5...multiply by -1 to make x positive
x = -5
