In this problem you would set these two equations equal to each other.
$8+ $1.50x = $10+ $1x
After this you would simplify the equation to isolate x (being the number of toppings you put on the pizzas)
$8+ 1.50x =$10+ 1x
-8 -8
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$1.50x = $2 + $1x
-1x -1x
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$.50x/.50 = $2/.50
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x= 4 toppings and the pizzas would equal $14 total
Percent means per one-hundred....
48(p/100)=12
48p=1200
p=25%
So $12 off of a $48 item is 25% off.
If 9 is 1/3 of the problem, then 9 x 3
= 27 would be the answer
F (1) - f (-1) / 1- (-1) = -1 -3 / 1+1 = -4/2 = -2
/ are fractions the equal signs should break them up, hope this helps.