Melody

WOW Chris - you have been a busy wolf !     

Just do in on a calculator

You should show how you get your answer Tiddle.  :)

It is the other way around Selena  :)

cost/bag = money/number of bags    

Good answer Selena  

I had never thought about that before.  Thanks Chris :))

step1:  Subtract 12.4x from both sides.

step2:  Add 17.2 to both sides

then think about what to do next

$$\\\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{f(x+h)-(x)}{h}\\\\
=\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{cos(x+h)-cos(x)}{h}\\\\
=\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{cosx*cosh-sinx*sinh-cos(x)}{h}\\\\
=\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{cosx(cosh-1)-sinx*sinh}{h}\\\\
=\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{cosx(cosh-1)}{h}-\frac{sinx*sinh}{h}\\\\
=\displaystyle \lim_{h\rightarrow 0}\;\;\;cosx*\frac{(cosh-1)}{h}-sinx*\frac{sinh}{h}\\\\
=cosx*0-sinx*1\\\\
=0-sin(x)\\\\
=-sin(x)$$

If you need these proved that also be done

$$\\\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{cosh-1}{h}=0\\\\
\displaystyle \lim_{h\rightarrow 0}\;\;\;\frac{sinh}{h}=1\\\\$$

15.4x-13.7=14x-17.2

Step1: Add 13.7 to both sides

Step2: Subtract 14x from both sides

step 3: think about what you neen to get rid of next and decide how this can be  achieved.

$$\\K^{0.3}L^{0.7}/L\\\\
=K^{0.3}L^{0.7-1}\\\\
=K^{0.3}L^{-0.3}\\\\
=\frac{K^{0.3}}{L^{0.3}}\\\\
=\left(\frac{K}{L}\right)^{0.3}$$