4m -21 = 3(5m - 1)
4m - 21 = 15m - 3
15m - 4m = -21 + 3
11m = -18
m = -18/11
To check:
LHS → 4 (-18/11) -21 = - 303/11
RHS → 3( 5(-18/11) - 1) = -303/11
LHS = RHS (The answer is right)
substitution method
Step-by-step explanation:
- use second equation
- make x subject of the formula
- put it back in the first equation
- solve to find the value of y
- substitute y value in any equation between the two.
- then you get x value
Given:
x: [1 2 3 4 5 6 7]
y: [9 9.5 10.25 11.25 12.5 14 15.75]
Let the function which models the data be
y(x) = ax² + bx + c
Apply the function to the first three data points
a + b + c = 9 .(1)
4a + 2b + c = 9.5 (2)
9a + 3b + c = 10.25 (3)
Subtract (1) from (2).
3a + b = 0.5
or
b = 0.5 - 3a (4)
Subtract (1) from (3).
8a + 2b = 1.25 (5)
Substitute (4) into (5).
8a + 2(0.5 - 3a) = 1.25
2a = 0.25
a = 0.125
From (4),
b = 0.5-3*0.125 = 0.125
From (1),
c = 9 - 0.125 - 0.125 = 8.75
The function is
y = 8.75 + 0.125x + 0.125x²
Check that the function works for x=4,5,6,7.
From the calculator, obtain
y(4) = 11.25 Correct
y(5) = 12.5 Correct
y(6) = 14 Correct
y(7) = 15.75 Correct
The graph of the function is shown below.
Answer: y = 8.75 + 0.125x + 0.125x²
The real-world description of the quantity four times x end quantity divided by 7 will be B. The cost per pizza for 4 pizzas divided by 7 people.
<h3>How to illustrate the information?</h3>
It should be noted that the information that is given is illustrated as:
four times x end quantity divided by 7
This will be:
= (4 × x) / 7
Therefore, the real description will be that the cost per pizza for 4 pizzas divided by 7 people.
In conclusion, the correct option is B.
Learn more about real world on:
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The decimal equivalent of 45⁰ 32’ 55” is 45.55⁰
<h3>Converting degrees into decimal</h3>
The given degree is:
45⁰ 32' 55''
This can be converted to decimal as shown below

This can be simplified further as:

Therefore, the decimal equivalent of 45⁰ 32’ 55” is 45.55⁰
Learn more on degrees to decimal conversion here: brainly.com/question/24226195
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