f1 maths! help me!

[匿名]

2008-07-24 12:08 am

ture or false ( t is ture , f is false)
1.there are 3 variables in the algebraic expression of 2a-b+c
2.in the algebraic expression of 4x-5y-1,the constant term is 1.
3. the algebraic expression of -3(χxχ)+4y cannot be simplified

4.Multiply a number χ by 8,then divide it by 3.what is the result?

5. simplify the following

(a) -4a+9a+5b-3b
(b)(2a)x(-3a)
(c)(15a-4a)x2a
(d)6a-56+13a/7a

6. if x=-4 and y=5, find the values of the following algebraic expression

(a)7x+6y
(b)x/2+y
(c)1/y+1/x
(d3(x+y)-4x

7.if a=6, b=8 and h=3,find the values of the following algebraic expression

(a)3b-a/h
(b)1/2(a+b)h
(c)1/3h+(axa)+b
(d)(hxh)-3b/2a

8.simplify the following

(a)r/5-r6
(b)b/3+2b/9-b/6
(c)(axaxaxaxa)/(axaxa)
(d)4(axaxaxa)(bxbxb)/6(axa)b

回答 (1)

還不明白的薑

2008-07-24 12:31 am

✔ 最佳答案

1.F (通常用x,y做 variables ,佢冇講就當a,b,c係constants)

2.F (係 -1)

3. T (除非你話χxχ=x^2)

4.8x/3

5.
(a) -4a+9a+5b-3b = 5a +2b

(b)(2a)x(-3a)= -6a^2

(c)(15a-4a)x2a =22a^2

(d)6a-56+13a/7a = 6a -56 +13/7 = 6a - 379/7

6. if x=-4 and y=5, find the values of the following algebraic expression

(a)7x+6y = -28+30 = 2

(b)x/2+y = -2 +5 = 3

(c)1/y+1/x =1/5 - 1/4 = -1/20

(d)3(x+y)-4x = 3(1)+16 = 19

7.if a=6, b=8 and h=3,find the values of the following algebraic expression

(a)3b-a/h = 24 - 2 = 22

(b)1/2(a+b)h = 1/2(14)(3) = 1/84

(c)1/3h+(axa)+b = 1/9 + 36 +8 = 397/9

(d)(hxh)-3b/2a= 9 - 24/12= 9 -2 = 7

8.simplify the following

(a)r/5-r/6= r/30

(b)b/3+2b/9-b/6 = 9b/18+4b/18-3b/18 = 10b/18 = 5b/9

(c)(axaxaxaxa)/(axaxa) = a^5/a^3 = a^2

(d)4(axaxaxa)(bxbxb)/6(axa)b = 4a^4b^3/6a^2b = 2a^2b^2/3

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