中一Maths,10分,快!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

1.=20y-4[3-2+6y]
=20y-4-24y
= -4-4y
=-4(1=y)

2.=[2a-a-b]-5b+5a
=6a-6b-5b+5a
=11a-11b
=11(a-b)

3.-2{a^2-ab-4a[2b-a-b]}
= -2a{a^2-ab-8ab+4a^2+4ab}
= -2{5a^2-5ab}
= -10a^3+10a^2b
=10a^2(b-a)

a^2=a二次方
a^3=a三次方

*2*=二次方 ,,,a*2*=a二次方


(1)= 20y-4(3-2+6y)
=20y-12+8-24y
= -4y-4

(2) =6(2a-a-b)-5a+5b
=6(a-b)-5a+5b
=6a-6b-5a-5b
=a-11b

(3) = -2a[a*2*-ab-4a(2b-a-b)]
=-2a(a*2*-ab-8ab+4a*2*+4ab)
=-2a(5a*2*-ab-4ab)
=-10a*3*+2a*2*b+8a*2*b

1)
20y-4[3-2(1-3y)]
=20y-4[3-2+6y]
=20y-12+8-24y
=-4y-4

2)
6[2a-(a+b)]-5(b-a)
=6[2a-a-b]-5b+5a
=12a-6a-6b-5b+5a
=a-11b

3)
-2a{a(a-b)-4a[2b-(a+b)]}
=-2a{a(2)-ab-4a[2b-a-b]}
=-2a{a(2)-ab-8ab+4a(2)+4ab}
=-2a(3)+2a(2)b+16a(2)b-8a(2)-8a(2)b
=-2a(3)+10a(2)b-8a(2)
備註：( )係次方

20y-4[3-2(1-3y)]
=20y-4(3-2-6y)
=20y-12+6y
=26y-12

6[2a-(a+b)]-5(b-a)
=6(2a-a-b)-5b+5a
=12a-6a-6b-5b+5a
11a-11b

-2a{a(a-b)-4a[2b-(a+b)]}
=-2a[a^2-ab-4a(2b-a-b]
=-2a(a^2-ab-8ab+4a^2+4ab)
=-2a^3+2a^2b+16a^2b-8a^3-8a^2b
=-10a^3+10a^2b

1.20y-4[3-2(1-3y)]

=20y-4(1+6y)

=20y-4-24y

= - 4y-4

=-4(y+1)

2.6[2a-(a+b)]-5(b-a)

=6 (2a-a-b)-5b+5a

=12a-6a-6b-5b+5a

=11a-11b

=11(a-b)



3.-2a{a(a-b)-4a[2b-(a+b)]}

= -2a[a(a-b)-4a(2b-a-b)]

= -2a(a^2-ab-4ab+4a^2)

= -2a(5a^2-5ab)

= -10a^3+10a^2 b

= -10a^2 (a-b)

Q1.
=20Y-4(-2+6Y)
=20y+8-24y
=-4y+8
=-4(y-2)

Q2.
=6(2a-a+b)-5b+5a
=6(a+b)-5b+5a
=6a+6b-5b+5a
=11a+b

Q3.
=-2a[a(a-b)-4a(2b-a+b)
=-2a(a2-ab)+4a(a-b)

1 .=20y-4[3-2(-2y)
=20y-4[3+2y]
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i don't know

1. 20y-4[3-2(1-3y)]
=20y - 4*3 -4*2(1-3y)
=20y-12-8(1-3y)
=20y-12-8*1-8*(-3y)
=20y-12-8+24y
=44y-20
=4(11y - 5)
2.6[2a-(a+b)]-5(b-a)
=6*2a-6(a+b)-5b-5(-a)
=12a-6a-6b-5b+5a
=11a-11b
=11(a-b)

3.-2a{a(a-b)-4a[2b-(a+b)]}
=-2(a^2)(a-b)-4a(2b)-4a(a+b)
=-2(a^3)+2(a^2)b-8ab-4(a^2)-4ab
= -2(a^3)-2(a^2)-12ab
= -2[(a^3)+(a^2)+6ab]

1. 20y-4(3-2-6y)
20y-4(1-6Y)
20Y-7+24Y
48Y-7

2. 6(2a2+2b)-5b-5a
12a2+16b-5b-5a
12a2+11b+5b

3. -2a
-2a
-2a3+2ab+18a2b-16ab
-2a3+18a2b-14ab