if a+b =7 and ab=12 , find 3(apower 2 – ab + b power 2) Plz tell me the answer fast plzIf u want 30 points About the author Hadley
Answer: 13 is the value of \bold{a^2-ab+b^2}a 2 −ab+b 2 Given: \begin{gathered}a+b=7 \\ab=12\end{gathered} a+b=7 ab=12 To find: The value of a^2-ab+b^2=?a 2 −ab+b 2 =? Solution: From the given \begin{gathered}a+b=7 \\ab=12\end{gathered} a+b=7 ab=12 To find the value of a^2-ab+b^2a 2 −ab+b 2 first express the term in to value given and then substitute the values and simplify it. The value of the term a^2-ab+b^2a 2 −ab+b 2 can be found. a^2-ab+b^2=a^2+2ab-3ab+b^2a 2 −ab+b 2 =a 2 +2ab−3ab+b 2 Using the identity \bold{a^2+2ab+b^2=(a+b)^2}a 2 +2ab+b 2 =(a+b) 2 =(a+b)^2-3ab=(a+b) 2 −3ab Substituting the given value \begin{gathered}=(7)^2-3(12)\\ =49-36=13\end{gathered} =(7) 2 −3(12) =49−36=13 Therefore, the value of\bold{a^2-ab+b^2}a 2 −ab+b 2 is 13. If a+b=7a+b=7 and ab=12.} Reply
Answer:
13 is the value of \bold{a^2-ab+b^2}a
2
−ab+b
2
Given:
\begin{gathered}a+b=7 \\ab=12\end{gathered}
a+b=7
ab=12
To find:
The value of a^2-ab+b^2=?a
2
−ab+b
2
=?
Solution:
From the given
\begin{gathered}a+b=7 \\ab=12\end{gathered}
a+b=7
ab=12
To find the value of a^2-ab+b^2a
2
−ab+b
2
first express the term in to value given and then substitute the values and simplify it.
The value of the term a^2-ab+b^2a
2
−ab+b
2
can be found.
a^2-ab+b^2=a^2+2ab-3ab+b^2a
2
−ab+b
2
=a
2
+2ab−3ab+b
2
Using the identity \bold{a^2+2ab+b^2=(a+b)^2}a
2
+2ab+b
2
=(a+b)
2
=(a+b)^2-3ab=(a+b)
2
−3ab
Substituting the given value
\begin{gathered}=(7)^2-3(12)\\ =49-36=13\end{gathered}
=(7)
2
−3(12)
=49−36=13
Therefore, the value of\bold{a^2-ab+b^2}a
2
−ab+b
2
is 13. If a+b=7a+b=7 and ab=12.}
== (a+b)2=a2+b2+2ab
72=a2+b2+2(12)
a2+b2=49−24=25