All Answers 358167 Answers

1). 12x ; 15x²  = 

Answer  = 60x² 

Factors are 4, 3, 5 and x^2   multiply them together......we get 60x^2

This one is correct

2). 2m; m2 – 4m + 4; 4m² – 8m 

Answer = 4m(m – 2)² 

2m,  m(m - 2) (m - 2), 4m(m - 2)

So ...  we need .... 4, m, and (m -2)^2  =

4m(m - 2)^2

And this one is correct, as welll !!!

Good job...!!

I still need help with this one

W = L + 4   ...so......

(L)(L + 4) = 320  simplify

L^2 + 4L - 320 = 0      factor

(L - 16) (L + 20) = 0       and setting each factor to 0, we have that x = 16 or x = -20

Reject the negative

So,  L = 16   and W = L + 4 = 20

29999999999999999999999970

Thank you. I did it correctly :)

You think?! Hmmm 

[(x - 3)/(x + 7)]  /  [(x + 1) /(x + 7) ]=    invert the second fraction and multiply

[(x - 3) / (x + 7) ] * [ (x + 7) / (x + 1)]  =   "swap" denominators

[(x - 3) / (x + 1)] * [(x + 7) /(x + 7) ] =

(x -3) / (x + 1)

.58333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333

I think so .

Two trains, each traveling at 60 kph [1 kilometer/minute] are on parallel tracks heading toward one another. One train is one-half kilometer long and the other train is two-thirds kilometer long. The fronts of the two trains pass the same point A at the same time. How many seconds does it take for the two trains to completely pass each other ?

$$v= 1\cdot \dfrac{km}{\text{min.}}\\\\
1.\ \text{ train speed*time: } \quad s_1 = vt \\
2.\ \text{ train speed*time: } \quad s_2 = vt \\\\
1.\ \text{ train long: } \quad l_1 = \frac{1}{2}\ km \\
2.\ \text{ train long: } \quad l_2 = \frac{2}{3}\ km \\\\
\boxed{s_1+s_2=l_1+l_2}\\\\
l_1+l_2 = vt+vt=2vt\\\\
\boxed{t=\dfrac{l_1+l_2}{2v}}\\\\
t = \dfrac{1}{2\cdot \dfrac{1\ km}{\ \text{min.}} }\cdot \left(
\dfrac{1}{2} + \dfrac{2}{3}
\right)\ km$$

$$\\t = \dfrac{1}{2}\cdot \dfrac{7}{6} \ \text{min.} \\\\
t = 0.58 \overline{3} \ \text{min.}\\ \\
t = \dfrac{1}{2}\cdot \dfrac{7}{6} * 60 \ s \\\\
t = \dfrac{7*10}{2}\ s = 7*5 \ s \\ \\
t = 35 \ s$$

HEX means hexadecimal system which includes 0-9, A-F.

Conversion is done in the similar manner we convert to binary

take the sine of the angle times the hyp. this will give you the side opp.

                 Rustynut "jus get n by "

If you know either the hyp. or the side adj. and the angle between them , take the sine of the angle times the hyp. = side opp. or take tangent of angle times side adj. = side opp. you realy dont need to use cosine at all.

                           Rustynut "jus get n by"

Check out this trian.  It goes from Shanghai to the Shanghai airport.

It is the worlds fastest.

It doesn't actually run on the track it is a magnetic leviatation train.

It shows two trains passing each other too but you have to be watching LOL

I have travelled on this train, it was certainly an experience.  :)))

Why is it 1/2 +2/3 Alan ?

Don't worry.  I've got it. :)))

On a scientific calculator, a fraction is just a division problem.

Show your steps.

    2(2x + 9) = 6

2(2x) + 2(9) = 6

       4x + 18 = 6

4x + 18 - 18 = 6 - 18

               4x = -12

            4x/4 = -12/4

                 x = -3

This can be written as: (cos(t) + 2)(2cos(t) - 1) = 0

1. cos(t) = -2  is not possible, so we must have

2. cos(t) = 1/2, which means that t = ±60°

.

The relative speed is 2 km/minute.  That is, assume one of the trains is stationary and the other is travelling at the combined speed of both.

The total distance to be travelled before they completely pass each other is (1/2 + 2/3)km = 7/6 km.

Total time is therefore (7/6)/2 minutes = 7/12 minutes = 7*60/12 seconds = 7*5 seconds = 35 seconds

.

.

2(2x+9)=6

X = -3