Question : If $a + b = 10$ and $ab = 9$, then the value of $a - b$ is:

Option 1: 7

Option 2: 5

Option 3: 8

Option 4: 6

Question : If a³ + b³ = 217 and a + b = 7, then the value of ab is:

Option 1: – 6

Option 2: – 1

Option 3: 7

Option 4: 6

Question : If $x^4+y^4=x^2 y^2$, then the value of $x^6+y^6$ is:

Option 1: 2

Option 2: 0

Option 3: 1

Option 4: 3

Question : If $a+b+c=1, ab+bc+ca=-1$ and $abc=-1$, then the value of $a^{3}+b^{3}+c^{3}$ is:

Option 1: 1

Option 2: – 1

Option 3: 2

Option 4: – 2

Question : If $A+\frac{1}{1+\frac{1}{2+\frac{1}{3}}}=\frac{9}{10}$, then the value of A is:

Option 1: $\frac{1}{5}$

Option 2: $\frac{3}{10}$

Option 3: $\frac{2}{5}$

Option 4: $\frac{1}{10}$