MCQ
If $\text{x}=\frac{2}{3+\sqrt7},$ then (x - 3)2=
- A1
- B3
- C6
- D7
✓
Answer
- 7
Solution:
$\text{x}=\frac{2}{3+\sqrt7}=\frac{2}{3+\sqrt7}\times\frac{3-\sqrt7}{3-\sqrt7}=\frac{2(3-\sqrt7)}{3-\sqrt7}\\ \ =\frac{6-2\sqrt7}{9-7}=\frac{6-2\sqrt7}{2}=3-2\sqrt7$
Now $(\text{x}-3)^2=(\not3-\sqrt7-\not3)^2=\big(-\sqrt7\big)^2=7$
Hence, correct option is (d).
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
$\sqrt[5]{6} \times \sqrt[5]{6}$ is equal to
→The lengths of a triangle are 6cm, 8cm and 10cm. Then the length of perpendicular from the opposite vertex to the side whose length is 8cm is:
The angles of a triangle are in the ration 3 : 5 : 7. The triangle is:
The side BC of $\triangle\text{ABC}$ is produced to a poin D. The bisector of $\angle\text{A}$ meet side BC in L. If $\angle\text{ABC}=30^\circ$ and $\angle\text{ACD}=115^\circ,$ then $\angle\text{ALC}=$
→- $85^\circ$
- $72\frac{1}{2}^\circ$
- $145^\circ$
-
$\text{None of these}$
The value of $\Big[(81)^{\frac{1}{2}}\Big]^{\frac{1}{2}}$ is:
→If each observation of the data is decreased by 8 then their mean:
The number $0.\overline{32}$ when expressed in the form $\frac{\text{p}}{\text{q}}$ $\big($p, q are integers and $\text{q}\neq0\big),$ is:
→If $4^x-4^{x-1}=24$, then $(2 x)^x$ equals
→The figure formed by joining the mid-points of the adjacent sides of a quadrilateral is a:
- Rhombus.
- Square.
- Rectangle.
- Parallelogram.
