CPhill

Or possibly....this........

(But I wouldn't bet on it.........!!!!..........You'll lose - on average - about 5 cents on the dollar every time you spin!!!)

OK, rosala, hang on for the ride!!

Let's call the first digit a and the second one b      .....    and   .....we know that

a + b = 9     (A)

So, let the larger number be written as

(10a + b)

And let the smaller number be wriiten as

(10b +a)

And their difference is 9  ...so...

(10a + b) - (10b + a) = 9     simplifying, we have

9a - 9b = 9       divide by  9

a - b = 1     (B)

So notice that we have two equations....(A) and (B)

a + b = 9

a - b =  1  

Let's just add them together to get rid of b

2a = 10     Divide by 2 on each side

a = 5    

And a + b = 9    so    5 + b = 9   So b =4

So the larger number = !0(5) + 4 = 54

And the smaller number = !0(4) + 5 = 45

And their difference is 9

Looks good.........Thumbs up from me !!

OK, Stacy, we have

8x^2  + 12x +2 = 0   Let's divide by 2 to reduce the coefficients

4x^2 + 6x + 1 = 0

This won't factor, so let's put it into the on-site solver...BTW...I know it has "real" solutions....

$${\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{6}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{1}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\frac{\left({\sqrt{{\mathtt{5}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}\right)}{{\mathtt{4}}}}\\
{\mathtt{x}} = {\frac{\left({\sqrt{{\mathtt{5}}}}{\mathtt{\,-\,}}{\mathtt{3}}\right)}{{\mathtt{4}}}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{1.309\: \!016\: \!994\: \!374\: \!947\: \!4}}\\
{\mathtt{x}} = -{\mathtt{0.190\: \!983\: \!005\: \!625\: \!052\: \!6}}\\
\end{array} \right\}$$And there are your two answers using the quadratic formula.... 

OK, rosala....let x be the first number and let y be the second number....and we're told that their ratio is 7 to 8   .....so we have  x to y = 7 to 8  ....or...put mathematically...

x/y =7/8   Now let's multiply both sides by "y"

x = (7/8)y    Notice that this is what x equals, so, since we are told that x +  y = 45, we have.......

(7/8)y + y = 45 

(7/8 + 1)y = 45       so  .........

(15/8)y = 45    Multiply by the reciprocal of (15/8)  = (8/15) on both sides

y = 45*(8 / 15)    The 45 and the 15 "cancel" to 3.....so we have

y = 3*8 = 24     And x = (7/8)y....so......

x = (7/8) (24) = 21

So the two numbers are 21 and 24

Note that the ratio of these is (21/24) = (7/8)....as requested.......

We need to solve for the radius. So using the "formula" for the surface area, we have

900*pi ft^2 = 4*pi*r^2       divide by pi

900 ft^2 = 4*r^2    divide by 4

225ft^2 = r^2         take the square root of each side

15 ft = r

Now, the "formula" for the volume is

V_s = (4/3)*pi*r^3

V_s = (4/3)*pi*(15ft)^3 = about 14,137 cu ft.

LOL!!!

Well......you gave 'em what they asked for......!!!

Your equation represents a line, and where a line intercepts the y axis (if it does), x =0.

So, letting x =0 in your equation, we have

4y = 12   

So...... y = 3

And there's the point of intersection with the y axis.......(0,3)

We can set this up as a proportion problem.

1.8/15 = x/20       So taking the cross- product, we have

20 * 1.8 = 15 * x    Divide by 15 on each side

20 * 1.8 / 15 =  2.4 hours

So

(2.4 - 1.8) = .6 hrs. = (.6 * 60minutes) =  36 minutes

4 gallons x $29 each = $116