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MaRussiya [10]
3 years ago
15

Solve -3x2 + 30x - 90 = 0.

Mathematics
1 answer:
FrozenT [24]3 years ago
6 0
-3x^{2}+30x-90=0 \\  \\ x^{2}-10x+30=0 \\  \\ \Delta=(-10)^{2}-4*1*30=100-20=-20 \\  \\  \sqrt{\Delta}= \sqrt{-20}=i \sqrt{20}   =2i \sqrt{5}  \\  \\ x_{1}= \frac{10-2i \sqrt{5} }{2} = 5-i \sqrt{5}   \\  \\ x_{2}= \frac{10+2i \sqrt{5} }{2} = 5+i \sqrt{5}
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Michelle has $8 and wants to buy a combination of dog food to feed at least two dogs at the animal shelter. A serving of dry foo
Ghella [55]

Answer:

PART A: Inequality (a)

Solve for y

The graph of y ≥ ⅓(8-x) is represented by the upper red line and all points in the shaded area below it. The line is solid because points on the line satisfy the conditions.

 Inequality (b)

Solve for y

The graph of y ≥ 2 - x is represented by the lower blue line and all points in the shaded area above it. The line is solid because points on the line satisfy the conditions. The solution lies in the purple area. It consists of all combinations of x and y that make y ≥ ⅓(8 - x) and y ≥ 2 - x. A practical but not a mathematical condition is that all values of x and y must be zero or positive numbers (for example, you can't have -2 servings of food), so I have plotted only the numbers in the first quadrant.

PART B: If a point is a solution of the system, then the point must satisfy both inequalities of the system.

For x=8, y=2. Verify inequality A  is not true. So the point does not satisfy inequality A. Therefore, the point is not included in the solution area for the system.

PART C: I choose the point (3,1) which is included in the solution area for the system.

That means Michelle buys 3 serves of dry food and 1 serving of wet food.

Step-by-step explanation:

Plz mark Brainliest?

3 0
2 years ago
Each state imposes its own excise tax on gasoline. Suppose, for example, that the state of Massachusetts imposes a state gasolin
vovangra [49]

Complete question :

Each state imposes its own excise tax on gasoline. Suppose, for example, that the state of Massachusetts imposes a state gasoline tax of $0.26 per gallon. Suppose further that an average of 1,022,000 gallons of gasoline per day were sold in Massachusetts in 2010. The average revenue from gasoline tax in 2010 is approximately?

Answer:

$265,720

Step-by-step explanation:

Given that:

State gasoline tax = $0.26 per gallon

Average number of gasoline sold per day = 1,022,000 gallons

. From the availabke information given :

Revenue generated = gasoline tax per gallon multiplied by the average number of gallons sold

= $0.26 * 1,022,000

= $265,720

3 0
3 years ago
8. Show work<br> here for<br> 5(3d+5e+3)
Darya [45]

Answer:

15d+25e+15

Step-by-step explanation:

Distribute

4 0
3 years ago
What is log base 7 of 252
rjkz [21]

Answer:

2.84

Step-by-step explanation:

Recognize that 252 = 7*36

and so:

log base 7 of 252 = log base 7 of 36 + log base 7 of 7, or

                                 log base 7 of 36 + 1

So the most you can simplify log base 7 of 252 is to write 1 + log base 7 of 36.

Or, if you want to use the change of base formula, you could do the following:

                                 log 36

log base 7 of 36 = -------------- = 1.84

                                  log 7

and so log base 7 of 252 would come out to

1 + log base 7 of 36  =  1 + 1.84  = 2.84

Check:  does 7^2.84 = 252?  YES.  So we know that:

 1 + log base 7 of 36 = 2.84

4 0
3 years ago
(ii) Using a calculator, or otherwise, determine the exact value, to one decimal place, of 8792-6886 12 X 9 ​
omeli [17]

Answer: I did it in the explanation thingy-

Step-by-step explanation:

Step 1. 8792 - 6886 = 1906

Step 2. 12 x 9 108

That... OR the answer is 205848X

3 0
2 years ago
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