The area of the triangle is 16 un squared
21.925....................Maybe
Hi there!

Find the perimeter using the formula:
P = 2l + 2w
It is given that the dimensions are 2.8 × 1.9 so plug these number into the equation:
P = 2(2.8) + 2(1.9)
P = 5.6 + 3.8
P = 9.4m
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
14:12
21:18
28:24
That should be the answer