Answer: A; 6.3%
Step-by-step explanation:
Problem 1
For the first problem, we first want to find y so that we can plug it into the expression.
We can use elimination method for the system of equations to solve.
3x+3y=21
3x-y=5
We subtract both equations to eliminate x.
4y=16 [divide both sides by 4]
y=4
Now that we know y, we can plug it into the expression.
[divide]
[subtract]
We know that the answer is A.
--------------------------------------------------------------------------------------------------------
Problem 2
For the second problem, we need to know how to calculate percent error. The formula for precent error is 
. We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.
[subtract]
[solve absolue value]
[divide]
[multiply]
Since the problem said to round to one decimal place, we know that the answer is 6.3%.
First, you need convert the decimals into fraction
0.26 = 26/100 = 13/50
The next step would be drawing 50 small boxes on a piece of paper. Make it colorless.
The final stap would be giving 13 out of those 50 boxes with different color (such as black), and you're done
It takes 3 years for the balance of account to be $ 221
<em><u>Solution:</u></em>
From given information,
Principal = $ 200
Rate of interest = 3.5 %
Amount after "n" years = $ 221
To find: number of years
In simple Interest,
Simple interest = amount earned - principal
Simple interest = 221 - 200 = 21
Thus simple interest earned is $ 21
<em><u>The formula for simple interest is given as:</u></em>
Where,
p is the principal
n is the number of years
r is the rate of interest per annum
Substituting the given values in formula,
Thus it takes 3 years for the balance of account to be $ 221
For this case we have a direct variation of the form:
Where,
- <em>k: proportionality constant
</em>
We must find the value of k.
For this, we use the following data:
Therefore, replacing values we have:
Rewriting:
Clearing the value of k we have:
Therefore, the direct variation equation is given by:
Answer:
The quadratic variation equation for the relatonship is:
Answer:
y = 0x - 2/3
Step-by-step explanation:
We are asked to find the equation of the line
Step1: find the slope
( 0 , -2/3) ( 3 , -2/3)
m = (y_2 - y_1 )/ (x_2 - x_1)
x_1 = 0
y_1 = -2/3
x_2 = 3
y_2 = -2/3
Insert the values into the equation
m =( -2/3 - (-2/3) / (3 - 0)
= -2/3 + 2/3 / 3
= 0 / 3
m = 0
Step 2: sub m into the equation
y = mx + c
y = 0x + c
Step 3: sub any of the two points given into the eqn
y = 0x + c
Let's pick ( 3 , -2/3)
x = 3
y = -2/3
-2/3 = 0(3) + c
-2/3 = 0 + c
c = -2/3
Step4: sub c into the equation
y = mx + c
y = 0x + c
y = 0x - 2/3
Therefore, the equation of the line is
y = 0x - 2/3
