I'm going to assume that you meant 450kg for the combined weight, 190kg more and 3 Llamas. I'm pretty sure Llamas and Okapis don't weigh 450450450kg (that's 993,073,252 pounds). :)
x= Okapi weight
y= Llama weight
EQUATIONS:
There are 2 equations to be written:
1) 450kg is equal to the weight of one Okapi and one Llama
450kg= x + y
2) The weight of 3 llamas is equal to the weight of one Okapi plus 190kg.
3y=190kg + x
STEP 1:
Solve for one variable in one equation and substitute the answer in the other equation.
450kg= x + y
Subtract y from both sides
450-y =x
STEP 2:
Substitute (450-y) in second equation in place of x to solve for y.
3y=190kg + x
3y=190 + (450-y)
3y=640 -y
add y to both sides
4y=640
divide both sides by 4
y=160kg Llama weight
STEP 3:
Substitute 160kg in either equation to solve for x.
3y=190kg + x
3(160)=190 + x
480=190 + x
Subtract both sides by 190
290= x
x= 290kg Okapi weight
CHECK:
3y=190kg + x
3(160)=190 + 290
480=480
Hope this helps! :)
It looks like you're given

Then by the additivity of definite integrals this is the same as

(presumably this is what the hint suggests to use)
Then by the fundamental theorem of calculus, we have

To answer this question you should begin with the coin that has a higher value. If you start with the dime and then just add the correct number of pennies to total $0.40, you will see that you will need 3 dimes ($0.30) and 10 pennies ($0.10).
I used a guess and check strategy starting with 2 dimes.
Answer:
A correlation exists in a scatter plot if there is a general trend in the outputs as inputs increase. If the outputs generally increase in value, then there is a positive correlation. If the outputs generally decrease in value, then there is a negative correlation.