A collection of nickels and dimes is worth $4.40. There are 53 coins in all. How many nickels are there?
Nickel is a US coin worth 5 cents or 0.05.
Dime is a US coin worth 10 cents or 0.10
n + d = 53
0.05n + 0.10d = 4.40
n = 53 - d
0.05(53 - d) + 0.10d = 4.40
2.65 - 0.05d + 0.10d = 4.40
0.05d = 4.40 - 2.65
0.05d = 1.75
d = 1.75 / 0.05
d = 35
n = 53 - d
n = 53 - 35
n = 18
There are 18 nickels and 35 dimes.
0.05n + 0.10d = 4.40
0.05(18) + 0.10(35) = 4.40
0.90 + 3.5 = 4.40
4.40 = 4.40
The row echelon form of the matrix is presented as follows;
<h3>What is the row echelon form of a matrix?</h3>
The row echelon form of a matrix has the rows consisting entirely of zeros at the bottom, and the first entry of a row that is not entirely zero is a one.
The given matrix is presented as follows;
The conditions of a matrix in the row echelon form are as follows;
- There are row having nonzero entries above the zero rows.
- The first nonzero entry in a nonzero row is a one.
- The location of the leading one in a nonzero row is to the left of the leading one in the next lower rows.
Dividing Row 1 by -3 gives:
Multiplying Row 1 by 2 and subtracting the result from Row 2 gives;
Subtracting Row 1 from Row 3 gives;
Adding Row 2 to Row 3 gives;
Dividing Row 2 by -2, and Row 3 by 18 gives;
The above matrix is in the row echelon form
Learn more about the row echelon form here:
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Answer:327
Step-by-step explanation:
20 pounds is 320 ounces and the lunch box plus that is 327 ounces
Answer:
Sum of the first 15 terms = -405
Step-by-step explanation:
a + 3d = -15 (1)
a + 8d = -30 (2)
Where,
a = first term
d = common difference
n = number of terms
Subtract (1) from (1)
8d - 3d = -30 - (-15)
5d = -30 + 15
5d = -15
d = -15/5
= -3
d = -3
Substitute d = -3 into (1)
a + 3d = -15
a + 3(-3) = -15
a - 9 = -15
a = -15 + 9
a = -6
Sum of the first 15 terms
S = n/2[2a + (n − 1) × d]
= 15/2 {2×-6 + (15-1)-3}
= 7.5{-12 + (14)-3}
= 7.5{ -12 - 42}
= 7.5{-54}
= -405
Sum of the first 15 terms = -405
Answer:
D option is correct
( At Q3 the market is wasting society's .. )
