Let L and S represent the weights of large and small boxes, respectively. The problem statement gives rise to two equations:
.. 7L +9S = 273
.. 5L +3S = 141
You can solve these equations various ways. Using "elimination", we can multiply the second equation by 3 and subtract the first equation.
.. 3(5L +3S) -(7L +9S) = 3(141) -(273)
.. 8L = 150
.. L = 150/8 = 18.75
Then we can substitute into either equation to find S. Let's use the second one.
.. 5*18.75 +3S = 141
.. S = (141 -93.75)/3 = 15.75
A large box weighs 18.75 kg; a small box weighs 15.75 kg.
It’s 28, 16 add 4 is 20 add 8 is 28
The probability that the student does not know the answer but he randomly guesses it is 0.146025
<h3>How to solve for the probability of having a correct guess</h3>
The question has only one right answer out of 5 choices.
Probability he answers incorrectly:
1 - 0.55 * 4/5
= 0.45 * 0.8
= 0.36
Probability he does not know answer but answers the question correctly

= 0.09/0.55+0.09
= 0.140625
Read more on probability here: brainly.com/question/24756209
Answer:
First, keep the first number, Second, change the operation from subtraction to addition, Next, get the opposite sign of the second number (known as the subtrahend) and Lastly, proceed with the regular addition of integers.
Step-by-step explanation:
Answer:
X= -3
Y= 7
a= -6
b = -28
C = 9
D= -7
Step-by-step explanation:
2x – 4y = -34
-3x - y = 2
2x – 4y = -34
-12x - 4y = 8
-14x = 42
X= 42/-14
X= -3
-3x - y = 2
-3(-3) -y = 2
9-y = 2
9-2= y
Y= 7
a = 2x
a= 2*-3
a= -6
b = -4y
b = -4*7
b = -28
C= -3x
C= -3*-3
C = 9
D= -y
D= -7