HannibalBarca

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:

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

Any more work for me to do?

Your welcome.

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 \(\boxed{A}\)

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 \(\boxed{D}\)

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 \(y-x=\boxed{-3}\)

I think hugo means that the person who asked the question give either +3 or -3 instead of +1 or -1. For example if I (the person who posted this question clicks the +1 or -1, I will give +3 or -3 instead.

Which answer is correct?

Shouldn't this post be off-topic?