Hey I don't know who Mhanifa is but 25 is correct, and I will put the entire explanation to how to get the answer here.
First of all the 2 lines on the left and right side of the triangles are means that those 2 lines are equal and thus forming a isosceles triangle.
This means that the bottom right angle is also 2x+2 degrees.
Now because all 3 angles in a triangle adds to 180 degrees, we can set up equation.
3x+1+2x+2+2x+2=180
Now combine like terms
7x+5=180
Then solve, first subtract 5 from both sides.
7x=175
Now divide 7 from both sides
x=25
Using sine law:
9/sinc = 15/sin22
sinc = 9sin22 / 15 = 0.225
so c = sin^-1(0.225) = 12.99 degrees ~~ 13 degrees
if B was required:
B = 180 - C - A ~~ 145
Assuming that you got the numbers right and that I did my calculations right, then the answer is <span>2998.45 tons.</span>
Step-by-step explanation:
Given:
and 
We can solve for f(x) by writing

Let 

Then


We know that f(0) = 0 so we can find the value for k:

Therefore,

If you have multiple equations with multiple variables, you can either do clever substitutions, or turn it into a matrix on which you can perform linear combinations or multiplications (Gauss elimination)
1 1 1 1
2 1 -1 8
1 -1 1 -5
(note how the above 3 rows represent the 3 equations, just got rid of the variables, plus sign and equals sign)
subtract row1 from row3, that eliminates x and z from row 3.
1 1 1 1
2 1 -1 8
0 -2 0 -6
divide row3 by -2, that will give y a factor of 1
1 1 1 1
2 1 -1 8
0 1 0 3
The last row now says y=3