Question
Factorise$ : 4a^2- 49b^2+ 2a - 7b$
✓
Answer
$4a^2- 49b^2 + 2a - 7b$
$= [ ( 2a )^2 - ( 7b )^2] + [ 2a - 7b ]$
$= [ 2a - 7b ][ 2a + 7b ] + [ 2a - 7b ] [ \because a^2 - b^2 = ( a + b )( a - b ) ]$
$= [ 2a - 7b ][ 2a + 7b + 1 ]$
$= [ ( 2a )^2 - ( 7b )^2] + [ 2a - 7b ]$
$= [ 2a - 7b ][ 2a + 7b ] + [ 2a - 7b ] [ \because a^2 - b^2 = ( a + b )( a - b ) ]$
$= [ 2a - 7b ][ 2a + 7b + 1 ]$
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
Express the following as a single logarithm :
$\frac{1}{2} \log _{10} 9+\frac{1}{4} \log _{10} 81+2 \log _{10} 6-\log _{10} 12$
→$\frac{1}{2} \log _{10} 9+\frac{1}{4} \log _{10} 81+2 \log _{10} 6-\log _{10} 12$
The volume$ V,$ of a cone is equal to one third of $\pi $ times the cube of the radius. Find a formula for it.
→Without using trigonometric tables, evaluate.
$\sec ^2 36-\cot ^2 54$
→$\sec ^2 36-\cot ^2 54$
In quadrilateral $ABCD,$ side $AB$ is the longest and side $DC$ is the shortest.
Prove that$: D >B.$
→Prove that$: D >B.$
Compare: $\sqrt{24}$ and $\sqrt[3]{35}$
→Factorise by the grouping method $:a^2+\frac{1}{a^2}-2-3 a+\frac{3}{a}$
→ABCD is a parallelogram in which $\angle A$ and $\angle C$ are obtuse. Points X and Y are taken on diagonal $B D$ such that $\angle AXD =\angle CYB =90^{\circ}$. Prove that : $XA = YC$.
→If an angle of a parallelogram is two-third of its adjacent angle, find the angles of the parallelogram.
Find the distance of the following points from the origin :
B (-5, 5)
B (-5, 5)
Find the values of $' a\ ' $ and $ ' b\ ' $ in each of the following :$\frac{\sqrt{7}-2}{\sqrt{7}+2}=a \sqrt{7}+b$
→