Math i need help please help

How do I find the answer to 2mn x 9mn if m=2 and n=4. I need help I dont get it

replace the m's with 2 and the n's with four
[(2)(2)(4)] X [(9)(2)(4)]=?

2mn x 9mn [m=2 and n=4]

[2x2x4] x [9x2x4]

[SOLVE WHAT'S IN THE FIRST BRACKET] 2x2=4; 4x2=8
[SOLVE WHAT'S IN THE SECOND BRACKET] 9x2=18; 18x4=72

8x72=576

your answer is 576!!!

No...

2mn x 9mn [m=2 and n=4]

[2x2x4] x [9x2x4]

[SOLVE WHAT'S IN THE FIRST BRACKET] 2x2=4; 4x4=16
[SOLVE WHAT'S IN THE SECOND BRACKET] 9x2=18; 18x4=72

16x72=1152

your answer is 1152...!

2mn x 9mn if m=2 and n=4

first plug in the numbers:
2(2)(4) x 9(2)(4)

Then multiply them to get your two separate numbers:
2x2x4=16 9x2x4=72

Then multiply the two numbers together:
16x72= 1152

 
mn = 2x4 = 8 on both sides of the equation. So,

2x8 x 9x8 = 16 x 72 = 1152

WHOA!

OHHH!!! I GOT A LiL MiXED UP!!! SORRY

 
Another solution:

2mn x 9mn = 18m²n²

= 18 x 4 x 16 = 1152