Factorization of Polynomials | Factorization of Polynomials Exercise 3C

Question

2𝑥^2 + 3𝑥 − 90

Solution
Transcript

"hello everyone i am sumanjali math tutor from leader learning welcome to question and answer session given question is 2 x square plus 3x minus 90 an expression was given we need to factorize this expression okay factorize this expression okay so this is a polynomial expression first step of okay so here i am writing the first step so in the first step we need to multiply the constant okay so we need to multiply the constant and coefficient of a okay coefficient of a okay so we need to multiply that okay so here constant value here constant value is 90 and coefficient of a is 2 okay so i'm multiplying 90 with 2 the value will be 180 okay now we need to factor we need to find factors for this product okay so we need to find factors factors of product that is equals to 180 okay so here the the factors should be in such a way that if we add or subtract we should get this particular value okay for example if we take 180 okay so if we divide 180 with 10 so we will be getting 18 that means 180 can be written as 10 into 18 okay but if we add 10 plus 18 we will be getting 28 and 10 minus 18 or 18 minus 10 we will get 8 okay so in no way we will getting 3 okay but we need to think about a factors so that if we add or subtract the factors we should get the coefficient of the middle term that is that is x coefficient okay yeah so here uh here the products of 180 can be written as 12 15 sir okay so 12 15's are 180 so that like yeah so we can write 3x as so i can write the equation expression again 2x square plus 3x minus 90 okay so i'm writing 3x as 2x square plus 15x plus i'm writing 12 x okay so i'm writing 12x first okay so minus 12 x plus 15 x okay so there is no standard process here we need to cross check again and again like that okay so now if we take common 2x here so it will be x will remain so here minus 6 will be there okay so now if i take 15 common here so x will be here and 15 60 90 so 6 will remain so here okay so we can write the given expression as product of x minus 6 and 2x plus 15 okay so the given expression is 2x square plus 3x minus 90 okay it can be written as x minus 6 into 2x plus 15 okay that's all please subscribe to the channel leader learning for further queries thank you"

Accepted Answer

2𝑥^2 + 3𝑥 − 90

We can further write it as

= 2𝑥^2 − 12𝑥 + 15𝑥 − 90

By taking out the common terms

= 2x (x – 6) + 15 (x – 6)

So we get,

= (2x + 15) (x – 6)

Factorization of Polynomials | Factorization of Polynomials Exercise 3C

Chapters in Secondary school Mathematics class 9 Rs Aggarwal

Exercises in Factorization of Polynomials

Question 36