MCQ
The polynomial whose zeroes are -5 and 4 is:
- A$x^2-5 x+4$
- B$x^2+5 x-4$
- ✓$x^2+x-20$
- D$x^2-9 x-20$
✓
Answer
Correct option: C.
$x^2+x-20$
(c)
Let $a=-5$ and $b=4$
Sum of zeroes
$
\Rightarrow a+b=-5+4=-1\quad \quad \ldots \ldots(1)
$
Product of zeroes
$
\Rightarrow a \times b=-5 \times 4=-20 \quad \quad \ldots \ldots(2)
$
The general equation of the quadratic is:$
x^2-(a+b) x+a b=0
$
Substituting values from equation 1 and 2 , we get,$
x^2+x-20=0
$
Hence, The polynomial whose zeroes are -5 and 4 is (c).
Let $a=-5$ and $b=4$
Sum of zeroes
$
\Rightarrow a+b=-5+4=-1\quad \quad \ldots \ldots(1)
$
Product of zeroes
$
\Rightarrow a \times b=-5 \times 4=-20 \quad \quad \ldots \ldots(2)
$
The general equation of the quadratic is:$
x^2-(a+b) x+a b=0
$
Substituting values from equation 1 and 2 , we get,$
x^2+x-20=0
$
Hence, The polynomial whose zeroes are -5 and 4 is (c).
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
In the figure, the area of ∆ABC (in square units) is:
A cubical ice $-$ cream brick of edge $22\ cm$ is to be distributed among some children by filling ice $-$ cream cones of radius $2\ cm$ and height $7\ cm$ up to the brim. How many children will get the ice $-$ cream cones?
→The distribution below gives the marks obtained by 80 students on a test:
The modal class of this distribution is:
| Marks | Less than 10 | Less than 20 | Less than 30 | Less than 40 | Less than 50 | Less than 60 |
| Number of Students | 3 | 12 | 27 | 57 | 75 | 80 |
If $n$ is any natural number, then $6^n-5^n$ always ends with:
→A bag contains $5$ red balls and some blue balls. If the probability of drawing a blue ball is double that of a red ball, then the number of blue balls is :
→The sum of the digits of a two-digit number is 15 . The number obtained by interchanging the digits exceeds the given number by 9 . The number is
If the height of a vertical pole is $\sqrt{3}$ times the length of its shadow on the ground, then the angle of elevation of the Sun at that time is
→In the gives figure, $AB$ and $AC$ are tangents to the circle with centre $O$ such that $\angle BAC =40^{\circ}$ Then $\angle BOC$ is equal to
→If $p = -7$ and $q = 12$ and $x^2 + px + q = 0,$ Then the value of $x$ is
→The lines represented by the linear equations y = x and x = 4 intersect at P. The coordinates of the point P are:
