Answer:
Katherine invested $12,000
Step-by-step explanation:
Use formula

where
I = interest,
P = principal,
r = rate (as decimal),
t = time (in years).
In your case,
t = 1 year,
r = 0.06 (or 6%)
P + I =$12,720, thus

9514 1404 393
Answer:
A. 3×3
B. [0, 1, 5]
C. (rows, columns) = (# equations, # variables) for matrix A; vector x remains unchanged; vector b has a row for each equation.
Step-by-step explanation:
A. The matrix A has a row for each equation and a column for each variable. The entries in each column of a given row are the coefficients of the corresponding variable in the equation the row represents. If the variable is missing, its coefficient is zero.
This system of equations has 3 equations in 3 variables, so matrix A has dimensions ...
A dimensions = (rows, columns) = (# equations, # variables) = (3, 3)
Matrix A is 3×3.
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B. The second row of A represents the second equation:

The coefficients of the variables are 0, 1, 5. These are the entries in row 2 of matrix A.
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C. As stated in part A, the size of matrix A will match the number of equations and variables in the system. If the number of variables remains the same, the number of rows of A (and b) will reflect the number of equations. (The number of columns of A (and rows of x) will reflect the number of variables.)
The measure of the unknown angle are; a) x = 89 degrees, b) p = 92 degrees.
<h3>What is the sum of all the angles of a regular polygon?</h3>
For a regular polygon of any number of sides, the sum of its exterior angle is 360°.
We already know that a 4-sided polygon's angles add up to 360 degrees.
So to find the value of x:
69 + 118 + 84 + x = 360
x = 360 - (69 + 118 + 84)
x = 89 degrees
b)
For a 4-sided polygon, we also know that the outside angles add up to 360 degrees.
So to find the value of p:
100 + 62 + 106 + p = 360
p = 360 - (100 + 62 + 106)
p = 92 degrees
Learn more about interior angles of a regular polygon here:
brainly.com/question/14173422
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Sandwich cost $7.70 and the soda costs $2.20.