(i) True
It has two terms so binomial.
(ii) True
It has single term so monomial.
(iii) False
(5a - 9b) - ( - 6a + 2b) = 5a + 6a - 9b - 2b = 11a - 11b
(iv) True
\(\frac{-8}{7}x^3y^4=\frac{-8}{7}\times8\times1=\frac{-64}{7}\)
(v) True
Taking the LCM of 4,6 and 2 = 12
\(\frac{3\text{x}\,+\,2\text{x}-\,6\text{x}}{12}=\frac{3}{4}\)
\(\Rightarrow\) -4x = 36
\(\Rightarrow\) x = -9
(vi) False
2x - 5 = 0
\(\Rightarrow \text{x}=\frac{5}{2}\)