Question
Son brought home a hand made worksheet that teacher did not go over and can't find examples anywhere.
Multiply each expression by its conjugate.
A. Square root of (13)-2
B. 2+3Square root (5)
C. Square root(3) minus Square root(7)
Thanks
Multiply each expression by its conjugate.
A. Square root of (13)-2
B. 2+3Square root (5)
C. Square root(3) minus Square root(7)
Thanks
Answers
When you multiply a binomial by its conjugate, you are duplicating the pattern of the difference of squares:
a^2 - b^2 = (a+b)(a-b)
so
(sqrt(13) - 2)(sqrt(13) + 2)
= 13 - 4
= 9
(2+3sqrt(5))(2-3sqrt(5))
= 4 - 45
= -41
try the last one, let me know what you get
a^2 - b^2 = (a+b)(a-b)
so
(sqrt(13) - 2)(sqrt(13) + 2)
= 13 - 4
= 9
(2+3sqrt(5))(2-3sqrt(5))
= 4 - 45
= -41
try the last one, let me know what you get
He got 10
not correct
(sqrt(3) - sqrt(7))(sqrt(3)+sqrt(7))
= 3 - 7
= -4
(sqrt(3) - sqrt(7))(sqrt(3)+sqrt(7))
= 3 - 7
= -4
Thank you
Related Questions
My 3rd grader brought home a math worksheet and I'm not sure about the answers, so I wanted another...
At a teacher’s conference on the first Saturday in November in Palm Springs, CA, 100
teachers meet...
1. On the one hand they want to go abroad, but on the other hand they want to save more money.
2....
1. He is a social science teacher.
2. He is a SS teacher.
3. She is a home economics teacher.
4...