Answer:
- large: 40 lbs
- small: 20 lbs
Step-by-step explanation:
A system of equations can be written for the weights of the boxes based on the relationships given in the problem statement. One equation will be for the total weight of 1 large and 1 small box; the other will be for the total weight of 70 large and 60 small boxes.
Let L and S represent the weights of Large and Small boxes, respectively. The system of equations is ...
L + S = 60 . . . . . . combined weight is 60 lbs
70L +60S = 4000 . . . . weight of boxes in the truck
__
We can solve this by substituting for s in the second equation.
70L +60(60 -L) = 4000
10L = 400 . . . . . . . . . subtract 3600, simplify
L = 40
S = 60 -L = 20
A large box weighs 40 pounds; a small box weighs 20 pounds.

= 3 Multiply both sides by 2
-4 + x = 6 Add 4 to both sides (to cancle out the -4)
x = 10
Answer:
3
+9x-30
Step-by-step explanation:
Multiply the three into each number
3
+9x-30
The correct answer is 6,8
Answer:
Option b - Subtract
Step-by-step explanation:
Given : Expression 
To find : Which operation should be completed first in the expression below?
Solution :
P - Parentheses
E - Exponent
D - Divide
M - Multiplication
A - Addition
S - Subtraction
In the first step we solve the bracket in the expression 
So, we do subtraction i.e. 12-8=4
Therefore, option b is correct.