Question

Show that (x - 2) is a factor of 3x
2 - x - 10. Hence, factorise 3x2 - x - 10.

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Answer 1

Answer:

(x-2) is a factor of 3x²-x-10  and

3x²-x-10 = (x-2)(3x+5)

Step-by-step explanation:

given, that (x-2) is a factor of 3x²-x-10

let p(x) = 3x²-x-10

consider, p(2)

= 3(2²)-2-10

= 3(4) - 12

= 12-12

=> p(2) = 0

so, by factor theorem, we can say that (x-2) is a factor of 3x²-x-10

take 3x²-x-10 = 3x²-6x+5x-10

                      = 3x(x-2)+5(x-2)

                      = (x-2)(3x+5)