(D) Given the quadratic expression $x^{2}-10x+21 = (x+m)(x+n)$.Expanding the right side,we get $(x+m)(x+n) = x^{2} + nx + mx + mn = x^{2} + (m+n)x + m

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

(D) Given the quadratic expression $x^{2}-10x+21 = (x+m)(x+n)$.Expanding the right side,we get $(x+m)(x+n) = x^{2} + nx + mx + mn = x^{2} + (m+n)x + mn$.Comparing the coefficients of $x$ and the constant term with the original expression $x^{2}-10x+21$,we get:$m+n = -10$$mn = 21$Therefore,the value of $m+n$ is $-10$.

Class 9 Mathematics Polynomials Mix Examples - Polynomials

Easy

If $x^{2}-10x+21=(x+m)(x+n)$,then $m+n = \ldots$

A
$10$
B
$7$
C
$21$
D
$-10$

Explore More

Browse All

Question Bank

All Subjects

Class 9 Questions

Class 9

Mathematics Questions

Chapter

Polynomials

Subtopic

Mix Examples - Polynomials

Factorise the following quadratic polynomial by splitting the middle term:
$x^{2}+10x+16$

Easy

View Solution

Check whether the polynomial $p(x) = x^{3} + 9x^{2} + 26x + 24$ is a multiple of $x + 2$ or not.

Medium

View Solution

If $49 x^{2}-b=\left(7 x+\frac{1}{2}\right)\left(7 x-\frac{1}{2}\right),$ then the value of $b$ is

Easy

View Solution

Determine which of the following polynomials has $(x-2)$ as a factor:
$A) 3x^2 + 6x - 24$
$B) 4x^2 + x - 2$

Medium

View Solution

Verify whether the following is True or False:
$-\frac{4}{5}$ is a zero of $4-5y$.

Easy

View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial

For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free

For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo

If $x^{2}-10x+21=(x+m)(x+n)$,then $m+n = \ldots$

Similar Questions

Factorise the following quadratic polynomial by splitting the middle term:$x^{2}+10x+16$

Check whether the polynomial $p(x) = x^{3} + 9x^{2} + 26x + 24$ is a multiple of $x + 2$ or not.

If $49 x^{2}-b=\left(7 x+\frac{1}{2}\right)\left(7 x-\frac{1}{2}\right),$ then the value of $b$ is

Determine which of the following polynomials has $(x-2)$ as a factor:$A) 3x^2 + 6x - 24$$B) 4x^2 + x - 2$

Verify whether the following is True or False:$-\frac{4}{5}$ is a zero of $4-5y$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Factorise the following quadratic polynomial by splitting the middle term:
$x^{2}+10x+16$

Determine which of the following polynomials has $(x-2)$ as a factor:
$A) 3x^2 + 6x - 24$
$B) 4x^2 + x - 2$

Verify whether the following is True or False:
$-\frac{4}{5}$ is a zero of $4-5y$.