Question 26254: How do you solve this problem?
The cube root of (9x + 19) = x + 1
I know that it would be simplified to 9x + 19 = (x + 1)^3, but how do you cube a binomial?
Answer by venugopalramana(3286)   (Show Source):
You can put this solution on YOUR website! The cube root of (9x + 19) = x + 1
I know that it would be simplified to 9x + 19 = (x + 1)^3, but how do you cube a binomial?
IF YOU DO NOT KNOW OR NOT TAUGHT THE FORMLA FOR CUBING A BINOMIAL...YOU CAN USE A SMALL TRICK..YOU DONOT KNOW (X+1)^3...SO PUT X+1=Y...THEN IT IS SIMPLY Y^3 ON THE R.H.S.
ON THE L.H.S..............9X+19=9(Y-1)+19=9Y-9+19=9Y+10...SO
Y^3=9Y+10...YOU WILL GET A VALUE FOR Y BETWEEN 3 AND 4...BUT I THINK YOUR PROBLEM SHOULD READ,IF YOU ARE IN AN ELEMENTARY STAGE IN THE TOPIC,
The cube root of (9x + 9) = x + 1
WHEN YOU WILL GET
Y^3=9Y
Y^3-9Y=0
Y(Y^2-9)=0
Y=0.....0R.....Y^2=9.....THAT IS Y=3......OR....-3
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