X-2y=1, solve for y, help!
1 answer:
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Xy=10
x+y=29
subtract x from both sides for second equation
y=-x-29
subsitute in second equaiton
x(-x-29)=10
-x^2-29x=10
add x^2+29x to both sides
x^2+29x+10=0
quadratic formula
if you have
ax^2+bx+c=0,
x=
so
x^2+29x+10=0
a=1
b=29
c=10
x=
x=
x=
x=
x=
or 
those are the 2 numbers
aprox=-28.65 and -0.349
x+y=29
subtract x from both sides for second equation
y=-x-29
subsitute in second equaiton
x(-x-29)=10
-x^2-29x=10
add x^2+29x to both sides
x^2+29x+10=0
quadratic formula
if you have
ax^2+bx+c=0,
x=
so
x^2+29x+10=0
a=1
b=29
c=10
x=
x=
x=
x=
x=
those are the 2 numbers
aprox=-28.65 and -0.349
Answer:
And we can find the nnumber of deviations from the mean for each limit given:
So we are 3 deviation from the mean and using the empirical rule we know that within 3 deviations from the mean we have 99.7% of the values
Step-by-step explanation:
Let X the random variable that represent the amount of time it takes him to arrive, and for this case we know the distribution for X is given by:
Where and
We want to find this probability:
And we can use the z score formula given by:
And we can find the nnumber of deviations from the mean for each limit given:
So we are 3 deviation from the mean and using the empirical rule we know that within 3 deviations from the mean we have 99.7% of the values