The second one for today is also about solving x
7x2−9=1
I tried this:
Multiply both sides by 7, I get:
49x2−9=7
72(x2−9)=7
2(x2−9)=1
2x2−18=1
then proceed untill
x2=9,5
The answer after this is incorrect. I was thinking of something else: After this line:
2(x2−9)=1, do this:
2(x+3)(x−3)=1
going further yields also a wrong answer. Please help me?..
The second one for today is also about solving
7x2−9=1
7x2−9=1|⋅77x2−9⋅7=77x2−9⋅71=7|ab∗ac=ab+c7x2−9+1=77x2−8=71x2−8=1x2=9|square root both sidesx=±3
Heureka,
thank you kindly...something so small that i just do not think of...I do appreciate your help!