Answer:
[tex]531441a^6-3542940a^5b+9841500a^4b^2-14580000a^3b^3+12150000a^2b^4-5400000ab^5+1000000b^6[/tex]
Step-by-step explanation:
1 n=0
1 1 n=1
1 2 1 n=2
1 3 3 1 n=3
1 4 6 4 1 n=4
1 5 10 10 5 1 n=5
1 6 15 20 15 6 1 n=6
This is where n is the exponent in
[tex](x+y)^n[/tex].
[tex](x+y)^6=1x^6+6x^5y+15x^4y^2+20x^3y^3+15x^2y^4+6xy^5+1y^6[/tex]
Now we want to expand:
[tex](9a-10b)^6[/tex] or we we can rewrite as [tex](9a+(-10b))^6[/tex].
Let's replace [tex]x[/tex] with [tex](9a)[/tex] and [tex]y[/tex] with [tex](-10b)[/tex] in the expansion:
[tex](x+y)^6=1x^6+6x^5y+15x^4y^2+20x^3y^3+15x^2y^4+6xy^5+1y^6[/tex]
[tex]((9a)+(-10b))^6[/tex]
[tex]=1(9a)^6+6(9a)^5(-10b)+15(9a)^4(-10b)^2+20(9a)^3(-10b)^3+15(9a)^2(-10b)^4+6(9a)(-10b)^5+1(-10b)^6[/tex]
Let's simplify a bit:
[tex]=9^6a^6-60(9)^5a^5b+15(-10)^2(9)^4a^4b^2+20(9)^3(-10)^3a^3b^3+15(9)^2(-10)^4a^2b^4+6(9)(-10)^5ab^5+(-10)^6b^6[/tex]
[tex]=531441a^6-3542940a^5b+9841500a^4b^2-14580000a^3b^3+12150000a^2b^4-5400000ab^5+1000000b^6[/tex]