Need all with working please
Will mark Brainliest

Step-by-step explanation:
Q1. (5^4)^2
= 5^8
Q2. x^2-x-12=0
x^2-x=12
x^2=12 or x=12
√x^2=√12
x=3. 464101615
x=3.5
Q3. e:f=2:3 and f:g=5:4
e:g= 2:4