B Nirmala Shastry Solutions for Exercise 3: MISCELLANEOUS EXERCISE

If $a-b=2,ab=15$, find$: a+b$. 

If $a-b=2,ab=15$, find$: a^3-b^3$. 

Without calculating the cubes, find the values of ${\left(25\right)}^3+{\left(-12\right)}^3+{\left(-13\right)}^3$.

If $2a+5b=11,ab=3$ find the value of $8a^3+125b^3$.

If $a+b=7,a^3+b^3=91$, find the value of $ab$.

If $a^2+b^2+c^2=26 \text{and} a+b+c=8$,find the value of $ab+bc+ca$.

If $a^2+b^2+c^2=65 \text{and} ab+bc+ca=8$,find the value of $a+b+c$.

If $5x-4y=6,xy=2$ find the value of $125x^3-64y^3$.