Alright - we want to start off by seeing if this number would be positive or negative. Debit means that you owe something, or that you have to pay that amount of money. If you had money to buy things with, that would be positive, but since debit means you haven’t paid something off yet, that is negative. Next, since you have 40 dollars in debt, you have -40 dollars.
Feel free to ask further questions!
Answer:
It appears to be substitution
Step-by-step explanation:
I think you are talking about system of equations
The first one is the answe<span>r.</span>
Answer:
The weighted average is of 69.94.
Step-by-step explanation:
Weighted average:
The weighed average is found multiplying each grade by its respective weight.
The grades, and weights are:
67 on the lab, with a weight of 23% = 0.23
69 on the first major test, with a weight is 21.5% = 0.215
85 on the second major test, with a weight is 21.5% = 0.215.
63 on the final exam, with a weight of 34% = 0.34.
Weighted average:

The weighted average is of 69.94.
Answer:
2 cows and 5 chickens.
Step-by-step explanation:
NOTE: This will be solved using simultaneous equations.
Let x = cows and y = chickens
1. form two equations
4x + 2y = 18 ... (1)
x + y = 7 .... (2)
2. make y (or x) the subject of one equation
x + y = 7
y = 7 - x ... (3)
3. Substitute (3) into (1)
4x + 2( 7 - x) = 18
4. solve for x
4x + 14 - 2x = 18
2x = 4
x = 2
5. Now substitute x value into equation (2)
x + y = 7
2 + y = 7
y = 5
∴ cows (x) = 2
chickens (y) = 5