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3 years ago

3. Simplify the following expression 2a(a+3)-4a4a-7)

Mathematics

1 answer:

LiRa [457]3 years ago

8 0

Answer:

-14a^2+6a-7

Step-by-step explanation:

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Which point is the image of point R(4, -7) first reflected across the x-axis and then across the y-axis?

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Answer:

(-4, 7)

Step-by-step explanation:

It would be the exact opposite of point R because it was rotated about 180 degrees from it's original location

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2 years ago

Help Question! Due Today

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5.B

what is 6

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Identify two ratios that are equivalent to 3:5

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3 years ago

What is the vertex form of Y = x2 - 6x + 6?

ahrayia [7]

Answer:

$\large\boxed{y=(x-3)^2-3}$

Step-by-step explanation:

The vertex form of a quadratic equation y = ax² + bx + c:

y = a(x - h)² + k

(h, k) - coordinates of a vertex

We have the equation y = x² - 6x + 6.

Convert to the vertex form:

$y=x^2-2(x)(3)+6\\\\y=\underbrace{x^2-2(x)(3)+3^2}_{(*)}-3^2+6\qquad\text{use}\ (a-b)^2=a^2-2ab+b^2\qquad(*)\\\\y=(x-3)^2-9+6\\\\y=(x-3)^2-3\to h=3,\ k=-3$

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2 years ago

Two pipes can fill a tank in 19 minutes if both are turned on. If only one is used, it would take 49 minutes longer for the smal

a_sh-v [17]

Answer:

The time taken by smaller pipe to fill the tank alone is 74.2 min

Step-by-step explanation:

Given as :

The time taken by two pipes to fill tank = 19 min

Let the time taken by larger pipe to fill tank = y

And the time taken by smaller pipe to fill tank = x

According to question

The smaller pipe takes 49 minutes longer than larger pipe

I.e x = y + 49

Now,

$\dfrac{1}{x}$ + $\dfrac{1}{y}$ = $\dfrac{1}{49}$

Or, $\dfrac{1}{y + 49}$ + $\dfrac{1}{y}$ = $\dfrac{1}{49}$

Or, $\dfrac{y + 49 + y}{y^{2} + 49 y }$ = $\dfrac{1}{49}$

Or, 2 y + 49 = $\dfrac{y^{2}+49y }{19}$

Or, 19 × ( 2 y + 49 ) = y² + 49 y

Or, 38 y + 931 = y² + 49 y

Or, y² + 49 y - 38 y - 931 = 0

or, y² + 11 y - 931 = 0

Or, Applying quadratic equation method to calculate the value of y

so, y = $\frac{- b \pm \sqrt{b^{2}-4\times a\times c}}{2\times a}$

Or, y = $\frac{- 11 \pm \sqrt{11^{2}-4\times 1\times (-931)}}{2\times 1}$

Or, y = $\frac{- 1 \pm \sqrt{121+3724}}{2}$

or, y = $\frac{- 1 \pm \sqrt{3845}}{2}$

or, y = $\frac{- 1 \pm 62.008}{2}$

∴ y = 25.2 , - 36.5

So, The time taken by larger pipe = y = 25.2 min

and the time taken by smaller pipe to fill the tank = y + 49 = 25.2 + 49 = 74.2 min

Hence The time taken by smaller pipe to fill the tank alone is 74.2 min answer

6 0

2 years ago