Factorisation | Factorisation Exercise 7E

Question

$x^3-144x=?$

$\text{ a. }x(x-12)^2$

$\text{ b. }x(x+12)^2$

c. x(x-12)(x+12)

d. none of these

Solution
Transcript

"hello students i am rita your math leader tutor and the today's question is x cube minus 144 x is equal to question mark and the options are a option x bracket x minus 12 whole square b option x bracket x plus 12 whole square and the c option x bracket x minus 12 x plus 12 and the d option none of these it is a mcq question and we have to find the correct option first of all the question is x cube minus 144 x now x we take x is common from both the terms then we got x square minus 144 as we know 100 we can write x square as x whole square and minus 144 is the perfect whole square of 12 so we can write it as 12 square as we know the identity that is a square minus b square is equal to a plus b a minus b now we use this identity in the question and we got the answer so when we use this identity then we got x plus 12 and x minus 12 now this is the answer of this question and the c option is the correct answer so c option is the answer i hope you like this video so please subscribe for more updates and do comment your question thank you "

Accepted Answer

let us consider $\left(x^{3}-144 x\right)=x\left(x^{2}-144\right.$ ) by taking x as the common factor

By using the formula $a^{2}-b^{2}=(a-b)(a+b)$

= x (x – 12) (x + 12)

Factorisation | Factorisation Exercise 7E

Chapters in Mathematics class 8th RS Aggarwal

Exercises in Factorisation

Question 3