CPhill

Seems to be working OK for me..........maybe you're punching the wrong buttons.......

If we have equal amounts of each mixture, then the percent of cream is 9%.

To see this, let's suppose that we mix x amount of 18% cream with x amount of 2% milk.

Then the amount of cream contained in the final mixture is just .18x, And the total amount of both mixtures is 2x.

So.....     (.18x) / (2x)  = .09 or 9%.

Taking 2x² + 6x - 5  =  0 and using the on-site calculator, we have....

$${\mathtt{2}}{\mathtt{\,\times\,}}{{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{6}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{5}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\frac{\left({\sqrt{{\mathtt{19}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}\right)}{{\mathtt{2}}}}\\
{\mathtt{x}} = {\frac{\left({\sqrt{{\mathtt{19}}}}{\mathtt{\,-\,}}{\mathtt{3}}\right)}{{\mathtt{2}}}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{3.679\: \!449\: \!471\: \!770\: \!336\: \!8}}\\
{\mathtt{x}} = {\mathtt{0.679\: \!449\: \!471\: \!770\: \!336\: \!8}}\\
\end{array} \right\}$$

We can use the Pythagoean Theorem for this......the length of the ladder  - 17 - is the hypoteneuse and 8 is one of the legs...so the remaining side =

√(17² - 8²) =  15 ft ....and that's how far the top of the ladder is up the wall

-(1 + 1/6)

"Three times a number" = 3n

And, the difference of three times a number and 7  = 3n-7......so

3n - 7 = 20      add 7 to both sides

3n = 27           divide each side by 3

n = 9

5 2/3 ÷ 11 4/5     converting both to improper fractions, we have

17/3 ÷ 59/5         invert the second fraction and multiply

17/3 x 5/59 =  

85/177

Using I = Prt , we have

I = 250(.072)(5) = $90

.05(1664+x)=x       simplify

83.2 + .05x = x      subtract .-05x from both sides

83.2 = .95x            divide both sides by .95

83.2/.95 = x = 87.5789473684210526

√97 = 9.8488578017961047