Whats the error? jonah says a common denominator for 3/4 and 2/5 is 9 whats the error. whats the answer

Jonah is incorrect because 3/4 and 2/5 don't have a common denominator of 9.Jonah probably added 4 and 5 together but that isn't the common denominator. You can check by doing this:
4,8,12,16,20,24,28,32,36,40
5,10,15,20,25,30,35,40,45,50

As you can tell 3/4 and 2/5 common denominator could be 20, 40 and many more but the more reasonable denominator would be 20. 

3 times 5  = 15        2 times 4= 8
  -                                           -
4 times 5  =  20            5  rimes 4=20

You have to multiply the numerator the same number that you multiplied it with the denominator to get 20

Four and five do not meet at nine. they meet at another number.
the answer is X/20

Hope I helped!   ;-)

step-by-step explanation:

when the line is solid:

it's either < or >

when the line is dashed:

it's either < or >

this > inequality sign means:

greater thanmore thanaboveexceeds

this < inequality sign means:

less thanfewer thanbelow

this > inequality sign means:

greater than/equal tono less thanat leastminimum of

this < inequality sign means:

less than/equal tono more thanat mostmaximum of

about the problem:

since the line is solid, that means it's either < or >

srry i'm not done ! i'll

What is the question?