Download App

Number systems — Maths STD 9 — Question

Gujarat BoardEnglish MediumSTD 9MathsNumber systems2 Marks
Question
Simplify the expression: $(\sqrt{5}-\sqrt{2})(\sqrt{5}+\sqrt{2})$
✓

Answer

$\left( {\sqrt 5 - \sqrt 2 } \right)\left( {\sqrt 5 + \sqrt 2 } \right)$ We need to apply the formula $\left( {a - b} \right)\left( {a + b} \right) = {a^2} - {b^2}$ to find value of ${\left( {\sqrt 5 + \sqrt 2 } \right)^2}$
$ (\sqrt 5 - \sqrt 2)(\sqrt 5 + \sqrt 2)$= $ [(\sqrt 5)^2 - (\sqrt 2)^2]$
$= 5 - 2 = 3$
Therefore, on simplifying $\left( {\sqrt 5 - \sqrt 2 } \right)\left( {\sqrt 5 + \sqrt 2 } \right)$,we get $3.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "2 Marks Questions" from Number systems→Number systems — all question types→Maths STD 9 question papers→Gujarat Board STD 9 question papers→Gujarat Board question paper generator→

Similar questions

Find whether the given equation have $x = 2, y = 1$ as a solution : $2x – 3y = 1$
→
Factorise:
$a^3+0.008$
 
→
Write the rationalisation factor of $\sqrt5-2.$
→
The largest sphere is carved out of a cube of side $10.5\ cm$. Find the volume of the sphere.
→
Factorise:
$4 a^2-9 b^2-2 a-3 b$
→
If each angle of a triangle is less than the sum of the other two, show that the triangle is acute-angled.
→
Simplify the following: $3\sqrt{3}+2\sqrt{27}+\frac{7}{3}$
→
Examine whether the following numbers are rational or irrational.
$\sqrt[3]{5}\times\sqrt[3]{25}$
→
Give an example of a binomial of degree $8.$
→
Find the area of a trapezium whose parallel sides are $9\ cm$ and $6\ cm$ respectively and the distance between these sides is $8\ cm.$
→