The given question is,
(70 ÷ 100)? + 3 = (0.49)4 x (0.343)4 ÷ (0.2401)4
As we know that
70 ÷ 100 = 0.7
0.49 = 0.7 2
0.343 = 0.7 3
0.2401 = 0.7 4
Put these value in given question , we will get
⇒ (0.7)? + 3 = (0.72)4 x ( 0.73 )4 ÷ ( 0.74 )4
⇒ (0.7) ? + 3 = 0.7 2 x 4 x 0.7 3 x 4 ÷ 0.7 4 x 4
⇒ (0.7) ? + 3 = 0.7 8 x 0.7 12 ÷ 0.7 16
Apply the law of Fractional Exponents and Laws of Exponents
(am)(an) = am+n
am÷an=am-n
Or
am/an=am - n
we will get,
⇒ (0.7)? + 3 = (0.7) 8 + 12 - 16
⇒ (0.7)? + 3 = (0.7) 20 - 16
⇒ (0.7)? + 3 = (0.7) 4
On comparing the exponents both sides, we get
? + 3 = 4
∴ ? = 4 - 3 = 1