All categories

2 years ago

Work out the value of 4(2x+3y) when x=8 and y=-3

Mathematics

1 answer:

meriva2 years ago

8 0

4(2 x 8 + 3 x (-3))
4(16 + (-9))
4(7)
=28

You might be interested in

The booster club for a high school football team sold adult and student tickets to a banquet.

USPshnik [31]

Answer:

<em>Hi There the correct answer to this is A 14</em>

Step-by-step explanation:

All you really need to do is Add 9 to 5 then you get your answer from 14.

4 0

3 years ago

Miguel borrowed $825 for a new couch. He will make 9 monthly payments of $95 to repay the loan. How much will he pay in interest

Leona [35]

Answer:

$30 is paid in interest.

Step-by-step explanation:

The couch costs $825 and Miguel will pay 9 * $95 = $855. So the amount of interest paid is how much in total was paid $855 minuse the cost of the couch $825, or $855-$825 = $30 in interest

3 0

3 years ago

Two spray paint machines are used to paint different portions of a large wall. The first machine (nicknamed "Paint Pro") is used

jonny [76]

Answer: The answer is 30 sq.ft/min and 25 sq.ft/min.

Step-by-step explanation: Given that there are two spray paint machines. The first machine (nicknamed "Paint Pro") is used for two hours and the second machine (nicknamed "Goldilocks") is used for an hour and a half. When they are working at the same time, they can paint 55 square feet per minute and together they painted 5850 square feet of wall.

Let 'x' and 'y' sq.ft/min be the portion of the wall painted by Paint Pro and Goldilocks respectively.

Then, according to the question, we have

$x+y=55,\\\\120x+90y=5850~~\Rightarrow 4x+3y=195.$

Multiplying first equation by 4 and subtracting the second equation from it, we have

$4y-3y=220-195\\\\\Rightarrow y=25,$

and

$x=55-25=30.$

Thus, Paint Pro will paint 30 sq.feet per minute and Goldilocks will paint 25 sq.ft per minute.

4 0

3 years ago

The author drilled a hole in a die and filled it with a lead weight, then proceeded to roll it 199 times. Here are the observed

Anton [14]

Answer with explanation:

An Unbiased Dice is Rolled 199 times.

Frequency of outcomes 1,2,3,4,5,6 are=28, 29, 47, 40, 22, 33.

Probability of an Event

$=\frac{\text{Total favorable Outcome}}{\text{Total Possible Outcome}}\\\\P(1)=\frac{28}{199}\\\\P(2)=\frac{29}{199}\\\\P(3)=\frac{47}{199}\\\\P(4)=\frac{40}{199}\\\\P(5)=\frac{22}{199}\\\\P(6)=\frac{33}{199}\\\\\text{Dice is fair}\\\\P(1,2,3,4,5,6}=\frac{33}{199}$

→→→To check whether the result are significant or not , we will calculate standard error(e) and then z value

$(e_{1})^2=(P_{1})^2+(P'_{1})^2\\\\(e_{1})^2=[\frac{28}{199}]^2+[\frac{33}{199}]^2\\\\(e_{1})^2=\frac{1873}{39601}\\\\(e_{1})^2=0.0472967\\\\e_{1}=0.217478\\\\z_{1}=\frac{P'_{1}-P_{1}}{e_{1}}\\\\z_{1}=\frac{\frac{33}{199}-\frac{28}{199}}{0.217478}\\\\z_{1}=\frac{5}{43.27}\\\\z_{1}=0.12$

→→If the value of z is between 2 and 3 , then the result will be significant at 5% level of Significance.Here value of z is very less, so the result is not significant.

$(e_{2})^2=(P_{2})^2+(P'_{2})^2\\\\(e_{2})^2=[\frac{29}{199}]^2+[\frac{33}{199}]^2\\\\(e_{2})^2=\frac{1930}{39601}\\\\(e_{2})^2=0.04873\\\\e_{2}=0.2207\\\\z_{2}=\frac{P'_{2}-P_{2}}{e_{2}}\\\\z_{2}=\frac{\frac{33}{199}-\frac{29}{199}}{0.2207}\\\\z_{2}=\frac{4}{43.9193}\\\\z_{2}=0.0911$