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# cphill plz hlep

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https://vle.mathswatch.co.uk/images/questions/question17507.png

https://vle.mathswatch.co.uk/images/questions/question17660.png

https://vle.mathswatch.co.uk/images/questions/question17547.png

May 4, 2020

#1
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Question 1

a) Substitute the $$x-y$$  as $$3$$

$$5 \cdot 3 = \boxed{15}$$

b) $$2(x-y)=2 \cdot 3=\boxed{6}$$

c) Multiply $$x-y=3$$ by $$-1$$ to get $$-x+y=-3$$ which equals $$y-x=\boxed{-3}$$

May 4, 2020
#2
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Question 2

$$f(x)=x^2 - x^3$$ is just a function, thus we can substitute $$-2$$ into every $$x$$.

Doing so we get $$f(-2)=(-2)^2-(-2)^3$$ which equals $$f(-2)=4+8=\boxed{12}$$

Therefore the answer is $$\boxed{D}$$

May 4, 2020
#3
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p;lz can you help me po this ine https://vle.mathswatch.co.uk/images/questions/question17843.png

Guest May 4, 2020
#4
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Question 3

Know that $$pressure=\frac{force}{area}$$, we can just substitute our known values into the equation.

The problem tells us that $$pressure=\frac{18N}{m^2}$$ and $$area=4m^2$$, thus we get $$\frac{18N}{m^2}=\frac{force}{4m^2}$$.

Let's assume $$f$$ as force. Cross multiplying we get $$(f)m^2=18N \cdot 4m^2$$.

Cancelling the $$m^2$$, we get we get $$f=\boxed{72N}$$.

Therefore the answer is $$\boxed{A}$$

May 4, 2020
#5
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thank you for helping i really appreciate it thnx

Guest May 4, 2020
#7
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HannibalBarca  May 4, 2020
#6
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For this one https://vle.mathswatch.co.uk/images/questions/question17843.png

a)

(i) $$\boxed{x=6, y=9}$$

(ii) To get the greatest possible value for $$3x-2y$$, we have to have the greatest number for $$x$$ and the least number for $$y$$

Therefore, $$x=10$$ and $$y=5$$ to get $$\boxed{20}$$

(iii) Similarly $$x=5$$ and $$y=10$$ to get $$\boxed{-5}$$

b)

Substituting the variables in, we get $$\boxed{-40}$$

May 4, 2020
#9
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https://vle.mathswatch.co.uk/images/questions/question17117.png

question b do you do 1.5x3=4.5

Guest May 4, 2020
#8
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Any more work for me to do?

May 4, 2020
#10
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just nee help on the question above plz

Guest May 4, 2020
#11
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For b), all you have to do is substitute the given values into the equation.

$$u = 3 m/s \\ a = 1.5 m/s^2 \\ t = 7 s$$

Thus we get:

$$v=3 m/s + 1.5m/s^2 \cdot 7 s \\ v=\boxed{13.5 m/s}$$

May 4, 2020