Algebra 1/2 Questions?

1) (m-12)/10 = (m+4)/11

you need to get rid of the whole numbers at the bottom, so you find the LCM (least common multiple) between the two whole numbers, which is 110(for 10 x 11 = 110).

so you get

-->110(m-12)/10=110(m+4)/11 , which simplifies into

-->11(m-12)=10(m+4)

now open parenthesis, and you get

-->11m-132=10m+40

solve for m.

-->m=172. :D

2)i'm guessing you meant a/(bx) - c = 0

so to solve that, you first move c over to the other side and get

-->a/(bx) = c

now multiply both sides by bx

-->a=bcx

solve for x.

-->a/(bc)= x

so x= a/(bc).

1) can't use your equation since it doesn't actually make sense.

Lets say you have 5x +5/4 = 2x + 10/6

Move the variables to one side and the numbers to the other

5x - 2x = 10/6 - 5/4

If you have to sum two fractions a/b + c/d, the sum is: (ad+bc)/bd, and if you need to subtract them, replace the + with a -.

Therefore you have:

3x = (10*4-6*5)/(6*4)

3x = (40-30)/24

3x = 10/24

x = 10/72

x = 5/36

2) I don't really understand this problem either. From what you have written you just need to make x the subject of the formula

a/b *x = c

x = cb/a

For #1 you need to multiply out whatever's on the bottom first... so

(m-12)/10 = (m+4)/11

becomes

11(m-12) = 10(m+4)

becomes

11m-132 = 10m+40

put m on one side by canceling (subtracting in this case)

11m(-10m)-132=40

m-132=40

then put your numbers on the other side by canceling again (adding in this case)

m=40(+132)

m=172

Now check your work by plugging your answer in

(172-12)/10 = (172+4)/11

160/10 = 176/11

16=16

Success.

1)

(m-12)/10 = (m+4)/11

the common denominator is 110 - multiply by 110

11(m-12) = 10(m+4)

11 m - 132 = 10 m + 40

m = 172

2)

a/ b x - c = 0

add c to both sides

a/ b x = c

multiply by b

a x = b c

divide by a

x = b c / a

multiply both sides by the least common denominator to get rid of fractions.

isolate the variable by the appropriate addition/subtraction

(m-12)/10 = (m+4)/11

multiply both sides by 110

11(m-12) = 10(m+4)

11m - 132 = 10m + 40

m = 172

a/b x - c = 0 <multiply both sides by b>

ax - bc = 0 <add bc to both sides>

ax = bc <divide both sides by a>

x = cb/a

1. cross multiply

move all the variables around so that x is by itself

It's least common multiple! 8)

Simply isolate X

a/b x - c = 0

Add c to both sides

a/b x = c

Now to get rid of fractions, multiply by the reciprocal.

(b/a)(a/b) x = (b/a)(c)

Leaves you with...

x = (b/a)(c)

Hope this is right.

cross multiply