DONT DO PART C you do not need to do that one i only need help on A and B please.

Mathematics

1 answer:

kap26 [50]3 years ago

6 0

Answer:

see explanation

Step-by-step explanation:

Given the 2 equations

x - y = 5 → (1)

4x + y = - 10 → (2)

Rearrange (1) expressing y in terms of x

(a)

y = x - 5 → (3)

Substitute y = x - 5 into (2)

4x + x - 5 = - 10

5x - 5 = - 10 ( add 5 to both sides )

5x = - 5 ( divide both sides by 5 )

x = - 1

Substitute x = - 1 into (3) for corresponding value of y

y = - 1 - 5 = - 6

(b)

As a check

Substitute x = - 1, y = - 6 into the left side of the 2 equations and if equal to the right side then they are the solution

(1 ) x - y = - 1 - (- 6) = - 1 + 6 = 5 ← True

(2) 4x + y = 4(- 1) + (- 6) = - 4 - 6 = - 10 ← True

Thus solution is (- 1, - 6 )

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Find the vertex of this parabola.<br><br><br><br> y = -2x2 + 4x + 12

STatiana [176]

For this case we have the following equation:
$y = -2x ^ 2 + 4x + 12
$
Deriving we have:
$y = -2x ^ 2 + 4x + 12

y '= -4x + 4$
We match zero:
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$
We clear the value of x:
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x = 4/4

x = 1$
Then, we substitute the value of x in the equation of the parabola:
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y = -2 + 4 + 12

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Thus, the vertex of the parabola is the ordered pair:
$(x, y) = (1, 14)$
Answer:
The vertice is:
$(x, y) = (1, 14)$

3 0

3 years ago

at a grocery store, an uncooked beef roast is on sale for $5.99/lb. At the same grocery store, prepared roast beef is available

-Dominant- [34]

Answer:

$7.58/lb

Step-by-step explanation:

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We know the price per lb of the raw roast.

Let's find the price per lb of the deli roast.

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