? asked in 科學及數學數學 · 1 decade ago

Solving Maths Equation!

Can some one help me solve the fowllowing equations:

1,Factorize:

a, x2-(y-z)2

b, ab-ad-bc+cd

2,Make a the subject of the fomula p=ab+2bc+3ac

3,Make m the subject of the fomula mx=2(m+c)

4,In fomula y=(1/2)(x+3) If the value of y is increased by 1, find the corresponding increase in the value of x.

5, Make x the subject of the fomula b=2x +(1-x)a

You can send the answer to my e-mail; laura40692@yahoo.com.hk

Thanks.

3 Answers

Rating
  • 1 decade ago
    Favorite Answer

    I think it is better to tell you in this way...

    1,Factorize:

    a, x2-(y-z)2

    Formula: x^2-y^2 = (x+y)(x-y)

    So, x2-(y-z)2

    = (x-y+z)(x+y-z)

    b, ab-ad-bc+cd

    Factorize it by grouping:

    =a(b-d) -c(b-d)

    =(a-c)(b-d)

    2,Make a the subject of the fomula p=ab+2bc+3ac

    Group the things contain a into group:

    p-2bc=a(b+3c)

    a= (p-2bc)/b+3c

    3,Make m the subject of the fomula mx=2(m+c)

    The same way:

    mx=2m+c

    m(x-2)=c

    m=c/(x-2)

    4,In fomula y=(1/2)(x+3) If the value of y is increased by 1, find the corresponding increase in the value of x.

    Expand:

    y=x/2 + 1.5

    Let see:

    If y = 1 ,

    1=x/2+1..5

    -0.5=x/2

    x=-1

    If y=2,

    2=x/2+1.5

    0.5=x/2

    x=1

    If y=3,

    3=x/2+1.5

    1.5=x/2

    x=3

    So we can see ,If the value of y is increased by 1,the corresponding increase in the value of x is 2.

    5, Make x the subject of the fomula b=2x +(1-x)a

    b=2x+a-ax

    b-a=x(2-a)

    x=(b-a)/(2-a)

    2009-01-04 13:39:14 補充:

    001 is wrong.

    a(b-d)-c(b-d)<>ac(b-d)

    when we factorize,

    we take out the common factor

    for example,

    in this question,

    the factor is (b-d)

    after we take out (b-d) from both terms,

    we remain: a and -c

    so the ans is (a-c)(b-d)

    2009-01-04 13:42:20 補充:

    Oh I want to ask a question:

    a, x2-(y-z)2

    it is x square or x times 2?

    if it is x times 2,

    Let me answer you (I answer in x square )

    2x - 2(y-z)

    =2(x-y+z)

    001 is wrong again!

    In -2(y-z)

    we have 負負得正right?

    so it is not -2z, is 2z

    Source(s): Me
  • 1 decade ago

    1a)x2-(y-z)2

    =2x-2y+2z

    =2(x-y+z)

    1b)ab-ad-bc+cd

    =a(b-d)-c(b-d)

    =(a-c)(b-d)

    2)p=ab+2bc+3ac

    p=ab+3ac+2bc

    p=a(b+3a)+2bc

    p-2bc=a(b+3a)

    a=(p-2bc)/(b+3a)

    3)mx=2(m+c)

    mx=2m+2c

    mx-2m=2c

    m(x-2)=2c

    m=(2c)/(x-2)

    4)If y = 1 ,

    1=x/2+1..5

    -0.5=x/2

    x=-1

    If y=2,

    2=x/2+1.5

    0.5=x/2

    x=1

    Therefore,if the value of y is increased by 1,the corresponding increase in the value of x is 2.

    5)b=2x +(1-x)a

    b=2x+a-ax

    b=2x-ax+a

    b=x(2-a)+a

    b-a=x(2-a)

    x=(b-a)/(2-a)

    Source(s): myself
  • 1 decade ago

    1)2x-2(y-z)

    =2x-2y-2z

    =2(x-y-z)

    2)ab-ad-bc+cd

    =a(b-d)-(bc-cd)

    =a(b-d)-c(b-d)

    =ac(b-d)

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