Answer:
(-3,1)
y= 1
x= -3
Step-by-step explanation:
4x-9y=-21
-4x-3y=9
solve the equation
4x=-21+9y
-4x-3y=9
substitute the value of 4x onto an equation
-1(-21+9y)-3y=9
multiply -1 to the numbers in parenthesis
-21+-9-3y=9
add -9 to 9 and put the negative on nine as a positive.
-21-3y=18
add -21 to 18 but since 21 is a negative the equation is subtraction.
-3y=-3
divide Both sides by -3
y=1
substitute the value of y into an equation
-4x-3•1=9
multiply 3 to 1
-4x-3=9
put -3 as a positive and add 3 to 9
-4x=12
divide both sides by -4
x= -3
(-3,1)
Given that Amistad deposited $2,163.27 in a savings account that earns 3.9% simple interest.
That means we need to use Simple interest formula to find the Amistad's account balance in nine months.
Simple interest formula is
A=P(1+RT)
Where P= principal amount = $2163.27
R= rate of interest = 3.9%= 0.039
T= time in years = 9 months = 9/12 years = 0.75
Now plug these values into above formula:
A=2163.27(1+0.039* 0.75)
A=2163.27(1+0.02925)
A=2163.27(1.02925)
A=2226.5456475
Hence Amistad's account balance in nine months will be approx $2226.55
Question 14:
We are given that:
C = πd
To solve for d, we need to isolate the d on one side of the equation. This means that we need to get rid of the π next to the d.
In order to do so, we can simply divide both sides of the equation by π as follows:
C/π = πd/π
d = C/π .........> The first option
Question (15):
We are given that:
d = rt
To solve for r, we need to isolate the r on one side of the equation. This means that we need to get rid of the t next to the r.
In order to do so, we can simply divide both sides of the equation by t as follows:
d/t = rt/t
r = d/t.........> The third option
Hope this helps :)
