幫我解决這些數學題!!!!!!!!!!!!Thx

1.Change the subject of the formula a=1分之2b+5 to b.
a = (1/2)b + 5
2a = b + 10
b = 2a - 10

如果x=-4 and y=5 / =分線
1. 7x+6y
= 7 * 4 + 6 * 5
=28 + 30
= 58

2. x/2+y
= (4) / 2 + 5
= 2 + 5
= 7

3. 1/y + 1/x
= 1/5 + 1/4
= 4/20 + 5/20
= 9/20

4. 3(x+y)-4x
= 3 (4 + 5) - 4 (4)
= 27 - 16
11

如果a=6,b=8 and h=3 / =分線
1.(3b-a)/h
= [(3(8) - 6) / 3
= 18/3
= 6

2.1/2(a+b)h
= 1 / [(6 + 8) * 3]
= 1/ [14 * 3]
= 1/ 42

3.1/3h+a的二次方+b
= 1/3 *3 + 6)^2 + 8
= 1 + 36 + 8
= 45

4.(h的二次方-3b)/2a
= (3^2 - 3 * 8) / (2 * 6)
= (-15) / (12)
= - 5/4

Simplify the following.
1.a五次方/a
= a ^5/ a
= 4 ^2

2.4a的四次方b的三次方/6a二次方b
= (4 * a^ 4)(b ^ 3) / (6)(a ^ 2)(b)
= (2 a^2 b^2) / 3

2007-09-03 07:23:08 補充：
Simplify the following. 1.a五次方/a= a ^5/ a= a ^ 4

2007-09-04 08:48:23 補充：
幫到你嗎?

1.a = (1/2)b + 5
2a = b + 10
b = 2a - 10

1. 7x+6y
= 7 * 4 + 6 * 5
=28 + 30
= 58

2. x/2+y
= (4) / 2 + 5
= 2 + 5
= 7

3. 1/y + 1/x
= 1/5 + 1/4
= 4/20 + 5/20
= 9/20

4. 3(x+y)-4x
= 3 (4 + 5) - 4 (4)
= 27 - 16
11

1.(3b-a)/h
= [(3(8) - 6) / 3
= 18/3
= 6

2.1/2(a+b)h
= 1 / [(6 + 8) * 3]
= 1/ [14 * 3]
= 1/ 42

3.1/3h+a的二次方+b
= 1/3 *3 + 6)^2 + 8
= 1 + 36 + 8
= 45

4.(h的二次方-3b)/2a
= (3^2 - 3 * 8) / (2 * 6)
= (-15) / (12)
= - 5/4

1.a五次方/a
= a ^5/ a
= a ^4

2.4a的四次方b的三次方/6a二次方b
= (4 * a^ 4)(b ^ 3) / (6)(a ^ 2)(b)
= (2 a^2 b^2) / 3