MCQ
Find m so that $(-3)^{m + 1} × (-3)^5 = (-3)^7$
- A$2$
- B$3$
- ✓$1$
- DNone of these
✓
Answer
Correct option: C.
$1$
$(-3)^{m + 1} × (-3)^5 = (-3)^7$
$(-3)^{m + 1 + 5} = (-3)^7$
$(-3)^{m + 6} = (-3)^7$
On both the sides powers have the same base different from $1$ and $-1,$
so their exponents must be equal.
Therefore, $m + 6 = 7$
or $m = 7 - 6 = 1$
$(-3)^{m + 1 + 5} = (-3)^7$
$(-3)^{m + 6} = (-3)^7$
On both the sides powers have the same base different from $1$ and $-1,$
so their exponents must be equal.
Therefore, $m + 6 = 7$
or $m = 7 - 6 = 1$
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
If $\left(\frac{5}{3}\right)^{-5} \times\left(\frac{5}{3}\right)^{11}=\left(\frac{5}{3}\right)^{8 x}$, then $x=$ ?
→There are $100$ voters. $50$ of them votes yes. What per cent voted yes?
→Mark $(\checkmark)$ against the correct answer: In the given figure, $AOB$ is a straignt line, $\angle\text{AOC}=56^\circ$ and $\angle\text{BOC}=\text{x}^\circ$ The value of $x$ is:
→Mark against the correct answer in the following: The boys and girls in a school are in the ratio $9 : 5.$ If the number of girls is $320,$ then the total strength of the school is:
→A circle is inscribed in a square of side 14 m. The ratio of the area of the circle and that of the square is
Every rational number is:
Which of the following pairs of angles is not a pair of supplementary angles?
lf $2a = 3b = 4c$, then $a : b : c =$
→$5.2$ is equal to:
→$9 \times\left(-\frac{1}{3}\right) \times(-3) \times\left(-\frac{1}{9}\right)=$
→