Taika invested a total of $ (a+b+c+ 900) × 1,000 into three investment accounts, paying 3%,4%, and 5% simple interest per year. The annual interest earned on the three investments was $ (c + 720) x 50. Twice as much money is invested at 3% as invested at 5%. Let x be the amount invested in the 3% account, y be the amount invested in the 4% account, and z be the amount invested in the 5% account. (a) Use the given information to write a system of linear equations for x, y, and z. (b) Convert this system to an augmented matrix. (c) Use a spreadsheet and Gaussian elimination with matrices to find the amount that was invested at each interest rate. Include two screenshots: (1) the formula view (or put in front to keep them from evaluating) of your spreadsheet (2) the results. Note: (Using methods other than Gaussian Elimination will result in heavy mark losses. You need to convert your matrix into row-echelon form.) (d) Check your answer for part (c) by substituting your solutions into the system of equations. NISS

Elementary Linear Algebra (MindTap Course List)
8th Edition
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Author:Ron Larson
Publisher:Ron Larson
Chapter3: Determinants
Section3.CM: Cumulative Review
Problem 6CM
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I attached the answer of part c(3) In view of part c solve d part
11:58 bo
a)
0 46 | | 2 61%
01:44
Augmented matrix
of corresponding to system is
1
3
4 5 : (+720) 5000
2
0
*
b
Step2
b)
we have
to solve this system using Graussian elimination.
to Convert system in row echlone.
form.
So, applying row operations.
R3 = R₂-2R₁
R₂= R₂-3R₁
I
1
: (a+b+c+ 900) 1000
0
1
2
(2c-3a-3b+900) 1000
o
-2
-3
(a+b+c+ 900) 2000
R3= R3+2R₂
T
1
1
: (a+b+c + 900) 1000
O
1
2 : (24-39-3b +900) 1000
O
1
: (C-49-46) 2000
R₂= R₂-3
1
1
: (a+b+c+900) 1000
O
O
: (13a +13b-2c + 900) 1000
O
1
: (c-49-4b) 2000
R₁ = R₁ - R₂-R3
O
0
(C-49-46) 1000
O 1 0 (139+13b-2C+900) 1000
0 O 1: (C-49-46) 2000
Hence the results are
x= ((-49-46) 1000, y = (139+13b-2(+900) 1000, Z = (C-49-46) 2000.
8
020
I : (a+b+c+ 900) 1000
J
LX
Do
Transcribed Image Text:11:58 bo a) 0 46 | | 2 61% 01:44 Augmented matrix of corresponding to system is 1 3 4 5 : (+720) 5000 2 0 * b Step2 b) we have to solve this system using Graussian elimination. to Convert system in row echlone. form. So, applying row operations. R3 = R₂-2R₁ R₂= R₂-3R₁ I 1 : (a+b+c+ 900) 1000 0 1 2 (2c-3a-3b+900) 1000 o -2 -3 (a+b+c+ 900) 2000 R3= R3+2R₂ T 1 1 : (a+b+c + 900) 1000 O 1 2 : (24-39-3b +900) 1000 O 1 : (C-49-46) 2000 R₂= R₂-3 1 1 : (a+b+c+900) 1000 O O : (13a +13b-2c + 900) 1000 O 1 : (c-49-4b) 2000 R₁ = R₁ - R₂-R3 O 0 (C-49-46) 1000 O 1 0 (139+13b-2C+900) 1000 0 O 1: (C-49-46) 2000 Hence the results are x= ((-49-46) 1000, y = (139+13b-2(+900) 1000, Z = (C-49-46) 2000. 8 020 I : (a+b+c+ 900) 1000 J LX Do
2. Taika invested a total of $ (a + b + c + 900) x 1,000 into three investment accounts, paying
3%,4%, and 5% simple interest per year. The annual interest earned on the three investments
was $ (c + 720) x 50. Twice as much money is invested at 3% as invested at 5%.
Let x be the amount invested in the 3% account,
and z be the amount invested in the 5% account.
y be the amount invested in the 4% account,
O
0
(a) Use the given information to write a system of linear equations for x, y, and z.
(b) Convert this system to an augmented matrix.
(c) Use a spreadsheet and Gaussian elimination with matrices to find the amount that was
invested at each interest rate.
Include two screenshots:
SS
(1) the formula view (or put in front to keep them from evaluating) of your spreadsheet
(2) the results.
Note: (Using methods other than Gaussian Elimination will result in heavy mark losses.
You need to convert your matrix into row-echelon form.)
(d) Check your answer for part (c) by substituting your solutions into the system of equations.
N
Transcribed Image Text:2. Taika invested a total of $ (a + b + c + 900) x 1,000 into three investment accounts, paying 3%,4%, and 5% simple interest per year. The annual interest earned on the three investments was $ (c + 720) x 50. Twice as much money is invested at 3% as invested at 5%. Let x be the amount invested in the 3% account, and z be the amount invested in the 5% account. y be the amount invested in the 4% account, O 0 (a) Use the given information to write a system of linear equations for x, y, and z. (b) Convert this system to an augmented matrix. (c) Use a spreadsheet and Gaussian elimination with matrices to find the amount that was invested at each interest rate. Include two screenshots: SS (1) the formula view (or put in front to keep them from evaluating) of your spreadsheet (2) the results. Note: (Using methods other than Gaussian Elimination will result in heavy mark losses. You need to convert your matrix into row-echelon form.) (d) Check your answer for part (c) by substituting your solutions into the system of equations. N
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