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3 years ago

B2 − 4ac for a = −2, b = 9, and c = −3

Mathematics

1 answer:

pshichka [43]3 years ago

4 0

Answer:

Step-by-step explanation:

Substitute the given values into the expression

b² - 4ac

= 9² - (4 × - 2 × - 3)

= 81 - (24)

= 81 - 24

= 57

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jennifers piggy bank contains nickles, dimes, and quarters. she has 4 more dimes then quarters and 3 times as many nickles as di

Liula [17]

Jennifer have 8 quarters, 12 dimes and 36 nickels.

Step-by-step explanation:

Given,

Worth of coins = $5.00 = 5*100 = 500 cents

One quarter = 25 cents

One dime = 10 cents

One nickel = 5 cents

Let,

x = number of quarters

y = number of dimes

z = number of nickels

According to given statement;

25x+10y+5z=500 Eqn 1

y = x+4 Eqn 2

z = 3y

z = 3(x+4) => z = 3x+12 Eqn 3

Putting value of y and z from Eqn 2 and 3 in Eqn 1

$25x+10(x+4)+5(3x+12)=500\\25x+10x+40+15x+60=500\\50x+100=500\\50x=500-100\\50x=400$

Dividing both sides by 50

$\frac{50x}{50}=\frac{400}{50}\\x=8$

Putting x = 8 in Eqn 2

$y=8+4\\y=12$

Putting x=8 in Eqn 3

$z=3(8)+12\\z=24+12\\z=36$

Jennifer have 8 quarters, 12 dimes and 36 nickels.

Keywords: linear equation, substitution method

Learn more about substitution method at:

#LearnwithBrainly

8 0

3 years ago

Please help me with these two questions asap!

inysia [295]

Answer:

3. x = 4, NOT extraneous

4. x=12, extraneous

Step-by-step explanation:

3. Solve for x, √(2x +1) = 3 and identify if it's an extraneous solution or not.

Since the square root is already isolated on its side, the first step is to put both sides to their square value to get rid of the square root. We then get:

2x + 1 = 9 => 2x = 8 => x = 4

To see if x = 4 is an extraneous solution, we enter it in the original equation and see if it works:

√(2x +1) = √(2 * 4 +1) = √9 = 3

3 equals 3... so it's NOT an extraneous solution

4. Solve for x, -4√(x-3) = 12 and identify if it's an extraneous solution or not.

This time the square root isn't alone on its side yet... so we have to isolate it, by dividing each side by -4:

-4√(x-3) = 12 becomes √(x-3) = -3

Then we raise each side to their square value to get rid of the square root:

x - 3 = 9 which becomes x = 12

To see if x = 12 is an extraneous solution, we enter it in the original equation and see if it works:

-4√(x-3) = -4√(12-3) = -4√(9) = -4 (3) = -12

-12 does not equal 12... so it's an extraneous solution

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4 years ago

The number of tickets sold for a concert during each hour ,x, of the first 10hours the tickets were in sale is given by g(x)=x^3

Mashutka [201]

The number in tickets sold A)107

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4 years ago

-4/5 divided by 1/3<br> Please asap

Snezhnost [94]

the straight up answer is -12/5

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3 years ago

Mr. Reddick has 74 total yards of red and blue felt to distribute to students in his art class. Each of his 20 students gets 2.5

notka56 [123]

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24/20 = x

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4 years ago