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3 years ago

Twice the difference of x and 2, is -25. What would this be?

Mathematics

1 answer:

Tom [10]3 years ago

4 0

Answer:

2(x + 2) = -25

2x +4 = -25

2x = -29

Step-by-step explanation:

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Domain of (x-5)(x+5)

soldier1979 [14.2K]

X2 -25 that’s the answer but it’s x squared 2 if that makes sense

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3 years ago

Cara has 25$ to buy dry pet food and treats for the animal shelter. A pound of dog food cost $2 and treats are $1 apiece. If she

alina1380 [7]

Let x be the number of treats bought
Let y be the pounds of food bought

25= 2y+x

Given that she has buys 9 pounds of dog food:

25= 2(9)+x
25=18 +x
25-18 =x
7=x

With the money she has left over, she can buy 7 treats.

Hope I helped :)

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3 years ago

How do I do question 9 & 11? Please help thank you!

Novay_Z [31]

<h2>9.</h2><h3>Given</h3>

sphere with radius 15 cm

linear approximation to the volume when the radius increases 0.4 cm

<h3>Solution</h3>

The equation for volume of a sphere is

... V = (4/3)π·r³

Differentiating gives

... dV = 4π·r²·dr

Filling in the given numbers gives

... change in volume ≈ 4π·(15 cm)²·(0.4 cm)

... = 360π cm³ ≈ 1130.97 cm³ . . . . . . volume of layer 4mm thick

<h2>11.</h2><h3>Given</h3>

an x by x by 2x cuboid with surface area 129.6 cm²
rate of change of x is 0.01 cm/s

rate of change of volume

<h3>Solution</h3>

The area is that of two cubes of dimension x joined together. The area of each such cube is 6x², but the two joined faces don't count in the external surface area. Thus the area of the cuboid is 10x².

The volume of the cuboid is that of two cubes joined, so is 2x³. Then the rate of change of volume is

... dV/dt = (d/dt)(2x³) = 6x²·dx/dt

We know x² = A/10, where A is the area of the cuboid, so the rate of change of volume is ...

... dV/dt = (6/10)A·dx/dt = 0.6·(129.6 cm²)(0.01 cm/s)

... dV/dt = 0.7776 cm³/s

5 0

3 years ago

The legs of a right triangle are 3 units and 6 units. What is the length of the hypotenuse? Round your answer to the nearest hun

garri49 [273]

C = $\sqrt{3 ^{2} + 6 ^{2} }$ = 6.7082

Round 6.7082
6.71

6.71 is your answer

8 0

3 years ago

Read 2 more answers

Can someone please explain to me how to do this.

JulijaS [17]

Y = x² - 4x + 4
y = 2x - 4

Find intersection of L and C:
x² - 4x + 4 = 2x - 4
x² - 6x + 8 = 0
<span> (x - 2)(x - 4) = 0
x = 2 or x = 4

When x = 2 , y = 2(2) - 4 = 0
When x = 4, y = 2(4) - 4 = 4

Points of intersection = A(2, 0) and B(4, 4)

Find the length of AB:

</span> $
\text {Length of AB}= \sqrt{(4-0)^2 + (4-2)^2} = \sqrt{16 + 4} = \sqrt{20} = 4.47 \text{ units}$
<span>
Answer: 4.47 units

</span>

4 0

4 years ago