Answer:

Step-by-step explanation:


Subtract 9 from both sides:


Add 6x to both sides:


Divide both sides by -4:


Answer:
4/5
Step-by-step explanation:
I THINK
Answer:
Just practice ,know different ways of solving it ,gain experince ,be smart and skilled.
Step-by-step explanation:
if you want to prove anuthing then go with the concept accoeding to the nature of the problem and there are almost many ways to prove anything so don't waste your time on way get on to the other ways.
It may not get proved at first time so keep on doing questions and when you have gained experience you know every nature of problems and then you are skilled properly.
Answer:
The area of the rectangle is increasing at a rate of
.
Step-by-step explanation:
Given : The width of a rectangle is increasing at a rate of 2 cm/ sec. While the length increases at 3 cm/sec.
To find : At what rate is the area increasing when w = 4 cm and I = 5 cm?
Solution :
The area of the rectangle with length 'l' and width 'w' is given by 
Derivative w.r.t 't',

Now, we have given




Substitute all the values,



Therefore, the area of the rectangle is increasing at a rate of
.