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Ratling [72]
3 years ago
5

Solve x and y simultaneously if:

Mathematics
1 answer:
Solnce55 [7]3 years ago
5 0

Answer:

make Y the subject in eqn........ 1

y + 7 = 2x

y = 2x - 7...........eqn 3

put y = 2x - 7 into eqn 2

x² - xy + 3y² = 15

x² - x(2x - 7) + 3(2x - 7)(2x - 7) = 15

x² - 2x² + 7x + 3(4x² + 14x -14x + 21) = 15

x² - 2x² + 7x + 12x² + 42x - 42x + 63 = 15

x² - 2x² + 7x + 12x² + 63 = 15

x² - 2x² + 12x² + 7x + 63 = 15

11x² + 7x + 63 - 15 = 0

11x² + 7x + 48 = 0

11x² + 7x = - 48

11x²/11 + 7x/11 = - 48/11

x² + 7x

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4. Timothy deposited $3500 into an accountthat pays 4.3% simple interest and keeps it
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6 0
3 years ago
BRAINLYEST FOR FIRST PERSON AND 5 STARS!!!!!!!!!!! simplify 3 x 5/6=
ale4655 [162]

Answer:

1st= 2 1/2

2nd= ???

3rd= 1/3

4th= 1/7

5th= 5/144

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
The Nut Shoppe sells walnuts for $4.00 a pound and cashews for $7.00 a pound. How many pounds of cashews should be mixed with 10
Anton [14]

Answer: He sold 10 pounds of cashews .

Step-by-step explanation:

Since we have given that

Selling price of walnuts = $4.00 a pound

Selling price of cashews = $7.00 a pound

Number of pounds of walnuts = 10

Let number of pounds of cashew be x

Total price at which he sold a mixture = $5.50

According to question,

10\times 4+x\times 7=(10+x)\times 5.50\\\\40+7x=55+5.5x\\\\7x-5.5x=55-40\\\\1.5x=15\\\\x=\frac{15}{1.5}\\\\x=10

Hence, he sold 10 pounds of cashews .

7 0
3 years ago
Estimate a 15% tip on a dinner bill of $47.67 by first rounding the bill amount to the nearest ten dollars.
DENIUS [597]

Answer:

The tip will be $7.2

And the total paid will be $55.20 or $55 rounded

Step-by-step explanation:

The equation is

48 x 0.15 = 7.2

48 + 7.2 = 55.2

55.2 rounded equals 55

7 0
3 years ago
Suppose that $a$ is a positive integer for which the least common multiple of $a+1$ and $a-5$ is $10508$. What is $a^2 - 4a + 1$
Nana76 [90]

Answer:

21022.

Step-by-step explanation:

Find the prime factors of 10508:

2 ) 10508

2 ) 5254

37 ) 2627

       71.

50208 = 2*2*37*71.

Now there is no integer value for a that would fit  (a+ 1)(a - 5) = 10508 .

But we could try multiplying the LCM by 2:-

= 21016  = 2*2*2*37*71.

= 2*2*37 multiplied by 2 * 71

= 148 * 142.

That looks promising!!

a - 5 = 142 and

a + 1 = 148

This gives  2a - 4 = 290

2a = 294

a = 147.

So substituting a = 147 into a^2 - 4a + 1 we get:

= 21022.

4 0
3 years ago
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