Answer:
7 Minutes and 22.5 Seconds Per Mile
Step-by-step explanation:
58/8 = 7.375
Then you have to get the .375 into minutes.
0.375*60 = 22.5
If you look at the quadratic formula:
x=(-b±√(b^2-4ac))/(2a)
We can say that -b=5, b=-5
If I read it right you had ±2√7 which is equal to ±√28, and we know b=-5 so:
±√(25-4ac)=±√28
And since 3=2a, a=1.5 making the above:
±√(25-6c)=±√28
25-6c=28
-6c=3
c=-0.5
So a=1.5, b=-5, and c=-0.5 thus
y=1.5x^2-5x-0.5
We can check this by reapplying the quadratic formula to the equation above
x=(5±√(25-4(1.5)(-0.5))/3
x=(5±√(25+3))/3
x=(5±√28)/3
x=(5±√(4*7))/3
x=(5±2√7)/3
Answer:
b)

Step-by-step explanation:
<u>Step(i)</u>:-
Given quadratic equation ax² + bx + c = 0
<u>step(ii)</u>:-
ax² + bx = -c
<u>Step(iii):</u>-
Dividing 'a' on both sides , we get


<u><em>Step(iv)</em></u>:-
Adding
on both sides , we get

Answer: -2x+3y = 21 which is choice C
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Work Shown:
The slope of the original line is -3/2. The perpendicular slope is 2/3. We flip the fraction and flip the sign. Multiplying the original slope (-3/2) and the perpendicular slope (2/3) will result in -1. Let's use this perpendicular slope and the point to find the equation of the perpendicular line in slope intercept form.
y = m+b
y = (2/3)x+b .... plug in the perpendicular slope
9 = (2/3)(3)+b .... plug in the point (x,y) = (3,9)
9 = 2+b
9-2 = 2+b-2 ... subtract 2 from both sides
b = 7
So y = (2/3)x+b turns into y = (2/3)x+7.
This equation is in slope intercept form.
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Let's convert to standard form
y = (2/3)x+7
3*y = 3*((2/3)x+7) ... multiply both sides by 3 to clear out the fraction
3*y = 3*(2/3)x+3*7 ... distribute
3y = 2x+21
-2x+3y = 21 .... get the x term to the other side (subtract 2x from both sides)