Comparison Problem

1. May 8, 2017

zak100

1. The problem statement, all variables and given/known data
LHS
(3y+2)/5
RHS
y

Which is greater?
2. Relevant equations

Equation is provided in the question
3. 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 cant be determined using the information provided.

Zulfi.

2. May 8, 2017

FactChecker

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.

3. May 8, 2017

Buffu

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

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

Maybe the domain is mentioned. did you wrote exact question ?

4. May 9, 2017

zak100

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.

Zulfi.

5. May 9, 2017

Staff: Mentor

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.