Compare LHS and RHS: Solve Problem Equation

  • Thread starter Thread starter zak100
  • Start date Start date
  • Tags Tags
    Comparison
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
4 replies · 2K views
zak100
Messages
462
Reaction score
11

Homework Statement


LHS
(3y+2)/5
RHS
y

Which is greater?

Homework Equations



Equation is provided in the question

The Attempt at a Solution


let y=1:
LHS= 1
RHS=1
So LHS & RHS are equal.

2ND try;
LET Y=0
LHS= 0.4
RHS= 0
So LHS is greater.
So Answer can't be determined using the information provided.

However my answer not correct. Some body please guide me.

Zulfi.
 
Physics news on Phys.org
Do you know how to find the values of y where they are equal? If so, you can just test once in each of the other sections and see how they compare.
 
zak100 said:

Homework Statement


LHS
(3y+2)/5
RHS
y

Which is greater?

Homework Equations



Equation is provided in the question

The Attempt at a Solution


let y=1:
LHS= 1
RHS=1
So LHS & RHS are equal.

2ND try;
LET Y=0
LHS= 0.4
RHS= 0
So LHS is greater.
So Answer can't be determined using the information provided.

However my answer not correct. Some body please guide me.

Zulfi.

##f(y) := (3y+2)/5 - y = (3y + 2 - 5y)/5 = (2 - 2y)/5##

##f(y) > 0## for ##y < 1## and negative elsewhere. So I think you are correct.

Maybe the domain is mentioned. did you wrote exact question ?
 
Hi,
Thanks. You are right. I skipped the assumption:
y>4. Now if y=5 then:
LHS= 17/3= 3.666
RHS=5 so RHS is greater.

Let y=20
LHS= 62/5= 12.4
RHS= 20

so again RHS is greater.

So RHS is greater.

Thanks for your comment.

Zulfi.
 
zak100 said:
LHS
(3y+2)/5
RHS
y
Assuming, as you later wrote, that y > 4, solve the inequality (3y + 2)/5 > y. This is equivalent to y < 1.
This means that if y < 1, the left side will be larger than the right side.

Put another way, if y < 1, the right side will be smaller than the left side. If y > 1, the right side will be larger. Your two examples, with y = 5 and y = 20 both support this conclusion.