MaxWong

\(\sqrt{18}=\sqrt2\times\sqrt9 = 3\sqrt2\)

Mathematically, 1+1 = 2

we can say that the bulbs are in parallel

and 

the power supply and the bulbs are in series

You have a spot the divide the current out and a spot to gather the current 

Like

         - - - - - - - - - - - |l - - - - - - - - - -

• -                                             -
• -                                             -
• - - - - - - - (bulb) - - - - - - - - - -
•                                               -
• - - - - - - - - (bulb) - - - - - - - - - 

 Ignore those black circles

and  ------ = connecting wires 

(bulb) = bulb, obviously

|l = power supply

= (4(8)-11)+(4(9)-11)+(4(10)-11)+(4(11)-11)+(4(12)-11)+(4(13)-11)+(4(14)-11)+(4(15)-11)+(4(16)-11)

= 280

\({6y}^{-4}=\frac{6}{y^4}\)

\({(6y)}^{-4}= \frac{1}{(6y)^4}= \frac{1}{1296y^4}\)

which one do you want

\(\frac{-90}{10}= - \frac{90}{10}= -9\)

There is always some word problems that people can't understand how to solve. 

Inequalities.

\(100>-5y\)

\(-100<5y\)

\(-20<y\)

\(y>-20\)

= 64 times (1-15%)

= 64 times 85%

= 54.4