Question

If a and b are roots of equation x2=7x + 4, then prove that a3=53a + 28

Answer 1

As the roots are a and b, we only required values in a.

So, Substitute x = a        (as it is a solution of it.)

Then, 

x² = 7x + 4                                     ...............1

Multiply "a" on both sides,

x³ = 7x² + 4x                                  ................2

Substituting 1 on 2

We get,

x³ = 7(7x +4) + 4x

x³ = 49x + 28 +4x

x³ = 53x + 4x

                                                                                          (HENCE PROVED)



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Answer 2

Answer:

Step-by-step explanation: