Solve each system of equations by writing a new system that eliminates one of the variables.

Mathematics

1 answer:

tamaranim1 [39]3 years ago

5 0

Answer:

$x=2\\y=-1$

Step-by-step explanation:

Let:

$3x+2y=4\hspace{5}(1)\\and\\4x+7y=1\hspace{5}(2)$

We need to eliminate one of the variables, so let's use elimination method. First multiply (1) by 4 and (2) by 3:

$4*(1)\equiv\hspace{5}12x+8y=16\\3*(2)\equiv\hspace{5}12y+21y=3$

Now subtract 3*(2) from 4*(1) in order to eliminate x:

$4*(1)-3*(2)\\12x-12x+8y-21y=16-3\\-13y=13$

Solving for y:

Multiplying both sides by -1/13

$y=-\frac{13}{13} =-1$

Finally, replacing the value of y in (1)

$3x+2*(-1)=4$

Solving for x:

add 2 to both sides:

$3x=6$

Multiply both sides by 1/3:

$x=\frac{6}{3} =2$

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If the filling equipment is functioning properly what is the probability that the volume of oil in a randomly selected barrel wi

Sophie [7]

Answer:

$P(X>55.4)=P(\frac{X-\mu}{\sigma}>\frac{55.4-\mu}{\sigma})=P(Z>\frac{55.4-55}{0.5})=P(Z>0.8)$

$P(Z>0.8)=1-P(Z\leq 0.8)$

$P(Z>0.8)=1-0.788=0.212$

Step-by-step explanation:

Assuming this previous info : "Trucks carry barrels of crude oil from a port in Texas to a distributer in New Mexico on long trailers. Filling equipment is used to fill the barrels with the oil. When functioning properly, the actual volume of oil loaded into each barrel by the filling equipment at the port is approximately normally distributed with a mean of 55 gallons and a standard deviation of 0.5 gallons. If the mean is greater than 55.4 gallons, the filling mechanism is overfilling."

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the amount filling of a population, and for this case we know the distribution for X is given by:

$X \sim N(55,0.5)$