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.

7 0

3 years ago

Combime like terms to create an equivalent expression -2.5(4x-3)

Ann [662]

Answer: -10x+7.5

Step-by-step explanation:

First multiply -2.5(4x)= -10x and then -2.5x-3= 7.5 it should be -10x+7.5

3 0

3 years ago

$700 is invested at 4% per annum. How long will it take for the amount to reach $784?

Blababa [14]

Answer:

3yrs

Step-by-step explanation:

Given parameters:

Capital = $700

Percentage interest = 4% per annum

Unknown:

Time it will take for amount to be = $784

Solution:

To find the simple interest on an amount;

I = $\frac{PRT}{100}$

P is the principal

R is the rate

T is the time

I is the interest

Insert the parameters:

I = $\frac{700x 4 x T}{100}$

I = 28T

So;

At the end of the duration:

Principal + Interest = Amount

700+28T = 784

28T = 784 - 700

28T = 84

T = 3yrs

5 0

2 years ago