Answer:
Option A is correct, i.e. x = -3, x = 7.
Step-by-step explanation:
Given the equation is x² -4x -21 = 0.
We can compare it with general quadratic equation i.e. ax² +bx +c =0.
then a = 1, b = -4, c = -21.
We can use Quadratic formula as follows:-
x = ( -b ± √(b²-4ac) )/2a
x = ( +4 ± √(16-4*1*-21) )/2*1
x = ( +4 ± √(16+84) )/2
x = ( +4 ± √(100) )/2
x = ( +4 ± 10 )/2
x = (4+10)/2 or x = (4-10)/2
x = 14/2 or x = -6/2
x = 7 or x = -3
Hence, option A is correct, i.e. x = -3, x = 7.
Minus 9x from both sides
-3y=-9x+12
divide both sides by -3
y=3x-4
Answer:
7.1 weeks to 68.4 weeks
Step-by-step explanation:
Chebyshev's Theorem states that:
75% of the measures are within 2 standard deviations of the mean.
89% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 38.1
Standard deviation = 10.1
Between what two search times does Chebyshev's Theorem guarantee that we will find at least 89% of the graduates
Between 3 standard deviations of the mean.
So from 38.1 - 3*10.1 = 7.8 weeks to 38.1 + 3*10.1 = 68.4 weeks
The expression m over 5 would represent the number of miles the bicyclist had traveled for a time of 5 minutes. This value is a value of speed. It is the magnitude of a velocity. It represents the total distance that is traveled for given certain period of time. It is a scalar quantity since it does not have any direction. It would have dimensions of distance per time with SI units of meter per second. Other units used are kilometer per hour and miles per hour. The vector quantity counterpart of this is called the velocity where it contains the magnitude of the speed and a direction. The direction of velocity is indicated by a positive and a negative sign.
Answer:
<1 = 54
Step-by-step explanation:
< CAB = <1 + <2
We have to assume that AP is a perpendicular bisector or we cannot solve the problem.
That would mean that <1 = <2
11x+9 = 6x+6x
11x+9 = 12x
Subtract 11x from each side
9 = 12x-11x
9 =x
We want <1
<1= 6x
<1 = 6*9
<1 = 54
