It's dependent on the context. A book may ask you to find the f'(x) of a function and you may have to use a u sub in your problem which requires you to find the dy/dx of what you substitute. So in this case both would be used.
Answer:
The correct answer is 25
Step-by-step explanation:
See the attached figure.
SAS similarity theorem mean that when two triangles have corresponding angles are congruent and corresponding sides with identical ratios the triangles are similar.
So, if ΔONM similar ΔSRQ by the SAS similarity theorem
∴∠N = ∠R
And

given that NM = 10 , NO = 8 , QR = x , RS = 20
∴
∴
So, the value of x will make ONM similar SRQ by the SAS similarity theorem = 25
Let s=number of seeds and t=number of days...
st=120 and (s+10)(t-2)=120
From the first we can say t=120/s, now using this value of t in the second equation gives us:
(s+10)(120/s-2)=120
(s+10)(120-2s)/s=120
(s+10)(120-2s)=120s
120s-2s^2+1200-20s=120s
2s^2+20s-1200=0
s^2+10s-600=0
(s+30)(s-20)=0, since s>0
s=20, and since she planted s+10 seeds per day to finish two days earlier:
20+10=30
She planted 30 seeds per day.
Answer:
6,780.00 is right answer try it