3l + 5w + 7h = 6
3l - 7w-5h = - 4
2l+w-4h = 1

5

Step-by-step explanation:

6-1=5

true? is that what you're asking or do you mean something else?

step-by-step explanation:

the true statements are:

r = set of real numbers

n = set of natural numbers, 1,2,

w = n u{0} = {0,1,}