6j + 1/3n = 134...multiply by 3....18j + n = 402
1/3j + n = 31....multiply by 3....j + 3n = 93
the multiplying by 3 is optional...I just did it because it is easier to work with equations when there are no fractions.
18j + n = 402....multiply by -3
j + 3n = 93
----------------
-54j - 3n = - 1206 (result of multiplying by -3)
j + 3n = 93
----------------add
-53j = - 1113
j = -1113/-53
j = 21
j + 3n = 93
21 + 3n = 93
3n = 93 - 21
3n = 72
n = 72/3
n = 24
so Jasons collection (j) consists of 21 books and Nathans collection (n) consists of 24 books
A) 2007
b) 120
c) the donations are decreasing as years increase
Answer:
For 1,000 bricks, the amount charged will be the same
Step-by-step explanation:
Let the number of bricks for which they charge the same amount be $x
Thus;
The total cost from the first company will
be;
250 + 0.2(x) = 250 + 0.2x
The second will charge;
400 + 0.05(x) = 400 + 0.05x
Since the amount charged will be equal at x bricks, we need to equate both;
400 + 0.05x = 250 + 0.2x
400-250 = 0.2x-0.05x
150 = 0.15x
x = 150/0.15
x = 1,000
