7x+55=90 angle in a rectangle is
7x=90-55 90
7x=35
x=35/7
x=5
The probability of pulling a boys name first is 8/13. Then the probably of pulling a girls second is 2/5.
These are easy if you know " FOIL ". That's a procedure that takes you through multiplying two binomials.
FOIL stands for
-- <u><em>F</em></u>irst terms
<span>-- </span><u><em>O</em></u>utside terms
<span>--<em> </em></span><u><em>I</em></u>nside terms
<span>--<em> </em><u><em>L</em></u></span>ast terms
and that's how you keep everything straight while you're doing it.
(ax + b) x (cx + d)
Multiply First terms . . . 'ax' times 'cx' = <em>acx²</em>
Multiply Outside terms . . . 'ax' times 'd' = <em>adx</em>
Multiply Inside terms . . . 'b' times 'cx' = <em>bcx</em>
Multiply Last terms . . . 'b' times 'd' = <em>bd</em>
Now addummup:
(ax + b) x (cx + d) = <em>acx² + adx + bcx + bd</em>
From there, you can look for opportunities to make it look cleaner and prettier ... factoring, combining like terms, etc.
