In analytical geometry, there are already derived equations to find the distance of lines and points as well as the angle made between two lines. As special case is when the other line is one of the coordinate axis. Then, the formula can be simplified to
tan θ =m, where m is the slope of the equation
In the next step, we also incorporate operations of calculus. Since the slope is equal to Δy/Δx, this is equivalent to dy/dx in calculus. Therefore, you can find the slope by differentiating the equation in terms of x.
<span>y-2x=7
y = 2x+7
dy/dx = 2 =m
So,
tan </span>θ = 2
θ = tan⁻¹(2)
θ = 63.43°
87. Juanita started with 40 dollars in her pocket.
Then she bought one CD for 7.99 dollars and 1 DVD for 8.99 dollars.
It has a sales tax of 7% on these items.
Plus she bought a lunch for 4.25 dollars including tax
Solve:
=> 7.99 dollars + 8.99 dollars = 16.98 dollars
=> 16.98 dollars * .07 = 1.2 dollars
=> 16.98 + 1.2 = 18.18 dollars
Plus the lunch
=> 18.18 + 4.25 = 22.43 dollars
=> 40 – 22.43 = 17.57 dollars
Original price is $150 so you times 150 by 0.40
150 x 0.40 = 60
So you take the $150 and you subtract $60 from $150
150 - 60 = 90
So the answer is $90
Answer:
15
Step-by-step explanation:
4x+y=8 so the answer is 15?
Here is the equation: x+(x+20) = 120
Since you can't combine anything yet, its x+x+20=120
You need to get x by itself
Minus 20 from both sides
Its x+x=100 now
Combine the x's which is now 2x
Now divide 100 by 2 which is 50
x=50
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Lets check:
50+(50+20)=120
Now combine the numbers in the parentheses
Its now 50+70=120
50+70=120 and 70-50=20
As you can see, he ran 50 minutes the first day and 70 minutes the second day
