Question

If a and b are roots of x^(2)-2x-7=0 then a^(3)+b^(3)=


pls answer it correctly no other talks

option
a)8
b)42
c)50
d)351​

Answer 1

Step-by-step explanation:

here comparing with Eqn

Ax²+Bx+C

then

A=1

B=-2

C=-7

$now sum of roots \\ a+b= \frac{-B}{A} = \frac{ - ( - 2)}{1} = \frac{2}{1} \\ \\ product s of roots = a \times b= \frac{C}{A} = \frac{ - 7}{1} \\ {a}^{3} + {b}^{3} = {(a + b)}^{3} - 3ab(a + b) \\ = {2}^{3} - 3( - 7)(2) \\ = 8 + 42 = 50$

Answer 2

Step-by-step explanation:

Siddharth niche da length of three iron rods rods a is 3 by 1 by 5 m long rodby is 13 by 7 m long and rod c is 5 by 8 m long what is the total length of the three rods?

Siddharth niche da length of three iron rods rods a is 3 by 1 by 5 m long rodby is 13 by 7 m long and rod c is 5 by 8 m long what is the total length of the three rods?

Siddharth niche da length of three iron rods rods a is 3 by 1 by 5 m long rodby is 13 by 7 m long and rod c is 5 by 8 m long what is the total length of the three rods?

Siddharth niche da length of three iron rods rods a is 3 by 1 by 5 m long rodby is 13 by 7 m long and rod c is 5 by 8 m long what is the total length of the three rods?

Siddharth niche da length of three iron rods rods a is 3 by 1 by 5 m long rodby is 13 by 7 m long and rod c is 5 by 8 m long what is the total length of the three rods?