Answer:
12.8mph
Step-by-step explanation:
Let 'w' represent her walking speed
->if her jogging speed is 8mph faster than her walking speed
Jogging speed= w+8
Using the time equation i.e time = dist/speed
For walking when distance is 8miles
time = dist / speed= 8/w hrs
For jogging when distance is 13miles
time = dist / speed= 13/(w+8) hrs
Equating the time
jog time = walk time
13/(w+8) = 8/w
By cross multiplying it
13w = 8w + 64
5w = 64
w=64/5
w=12.8mph
Therefore, 12.8mph is her walking speed.
You have to add the according numbers bcoz the a and b are just adding up
3+6 9
Answer: 49x^2=-21x-2 quadratic functions -1/7and -2/7
Step-by-step explanation:
Quadratic function:
In elementary algebra, the quadratic formula is a formula that provides the solution to a quadratic equation. There are other ways of solving a quadratic equation instead of using the quadratic formula, such as factoring, completing the square, graphing and others.
Move terms to the left side
49 =-21x-2
49 -(-21x-2) =0
Distribute
49 -(-21x-2) =0
49+21x+2=0
Use the quadratic formula
x=(-b±√ -4ac ) / 2a
Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.
49+21x+2=0
let, a=49
b=21
c=2
Replace with values in this equation
X=(-b±√ -4ac ) / 2a
Simplify
Evaluate the exponent
Multiply the numbers
Subtract the numbers
Evaluate the square root
Multiply the numbers
x=(-21±7) /98
Separate the equations
To solve for the unknown variable, separate into two equations: one with a plus and the other with a minus.Separate
x=(-21+7) /98
x=(-21-7) /98
Solve
Rearrange and isolate the variable to find each solution
x=-1/7
x=-2/7
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Answer: sin = ±
Step-by-step explanation:
We very well know that,
cos2A=1−2sin²A
⟹ sinA = ±
As required, set A = & cos a= ,thus we get
sin =±
∴ sin =± = ±
since ,360° < <450°
,180° < <225°
Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative.
hope it helped!