(a-b)(a^2+b^2)...plz answer me fast and correctly
Answers
Answer:
Here are two very important and common expressions:
in one step, be able to go from here ...
(
a
+
b
)
2
=
(
a
+
b
)
(
a
+
b
)
=
a
2
+
a
b
+
a
b
+
b
2
=
... to here
a
2
+
2
a
b
+
b
2
(a+b)2⏞in one step, be able to go from here ...=(a+b)(a+b)=a2+ab+ab+b2= a2+2ab+b2⏞... to here
in one step, be able to go from here ...
(
a
−
b
)
2
=
(
a
−
b
)
(
a
−
b
)
=
a
2
−
a
b
−
a
b
+
b
2
=
...to here
a
2
−
2
a
b
+
b
2
(a−b)2⏞in one step, be able to go from here ...=(a−b)(a−b)=a2−ab−ab+b2= a2−2ab+b2⏞...to here
You should (eventually) be able to multiply out expressions like these without writing down any intermediate results.
Be careful!
One of the most common algebra mistakes is to think that
(
a
+
b
)
2
(a+b)2 is equal to
a
2
+
b
2
a2+b2.
NOT SO!!!
You've got the Firsts (‘F’) and the Lasts (‘L’)
but have left out the Outers (‘O’) and the Inners (‘I’)!
One of my students (Ian Sullivan) came up with this memory device
as a reminder that the squares
(
a
+
b
)
2
(a+b)2 and
(
a
−
b
)
2
(a−b)2 require FOILing:
Okay, square—go foil yourself!
EXAMPLES:
Simplify:
(
x
−
2
)
2
(x−2)2
Answer: x^2 - 4x + 4
Note: Use the ‘ ^ ’ key for exponents in the exercises below.
Input your answer in the most conventional way.
That is, even though 4 - 4x + x^2 is a correct answer,
it isn't recognized as correct by this program.
Simplify:
(
3
x
+
y
)
2
(3x+y)2
Answer: 9x^2 + 6xy + y^2
Note: Variables must be typed in the order they appear,
going from left to right, for your answer to be recognized as correct.
That is, even though 9x^2 + 6yx + y^2 is a correct answer,
it isn't recognized as correct by this program.
Step-by-step explanation:
please mark me as brainlist
