51, because 39+12=51. You just add both parts of the tree. Please Rate Brainliest.
Answer:

Step-by-step explanation:
Since question already gives the number of dollars she will tip, I'm assuming it's asking for percent tipped.
Because the total is $75 and Theresa is tipping $6, she is tipping
of the total. To convert this to a percentage, multiply by 100: 
Rileyflipflop,

= 8

, since she can't buy half a CD, she's limited to no more than 8 CDs. If x = the cost of one CD, then x CDs cost $18x. Since we are limited to $153, our equation looks like... 18x < 153x < 8

Again, since we can't buy half a CD, your answer should actually be... x ≤ 8 since we can buy 8 CDs or fewer.
The inverse relation would be each of these ordered pairs switched.
{(1, -4), (3, -4), (-8, 0), (-9, 8)}
This is because when you create an inverse equation, all of the inputs become outputs and all of the outputs become inputs. Therefore, the ordered pairs simply switch.
Notice that the 2 expressions have 2 common terms.
(r-s) is just (s-r) times (-1)
similarly
(t-s) is just (s-t) times (-1)
this means that :
(r-s) (t-s) + (s-r) (s-t)=-(s-r)[-(s-t)]+(s-r) (s-t)
the 2 minuses in the first multiplication cancel each other so we have:
-(s-r)[-(s-t)]+(s-r) (s-t)=(s-r) (s-t)+(s-r) (s-t)=2(s-r) (s-t)
Answer:
d)<span>2(s-r) (t-s) </span>