How do you solve for d?

Question

a/b=c/d


Also, how would you solve for b in this case:

5/2=1/2(b-c)

Answer 1

> How do you solve for d?

When the variable you're solving for is in the denomitar of a fraction, its a good idea to multiply both sides of the equation by that denominator.

So, first multiply both sides by "d"

d(a/b) = d(c/d)

That makes the "d" cancel out on the right side:

d(a/b) = c

Next, multiply both sides by "b/a", which will make the "a/b" cancel on the left side:

d(a/b)(b/a) = c(b/a)
d = c(b/a)

You now have "d" by itself on one side: so you've solved for d.

> Also, how would you solve for b in this case:

Always try to "strip away" the things that are surrounding your variable that you're solving for. First, strip away the "1/2" by multiplying by 2/1 (that is, by 2):

2(5/2)=2(1/2(b-c))

The "2" cancels with the "1/2" on the right side, so:

2(5/2) = (b-c)

Also, notice that the 2's cancel on the left side too, so:

5 = (b-c)

Next, "strip away" the "c" on the right side, by adding "c" to both sides of the equation:

5 + c = (b-c) +c

5 + c = b

You now have "b" on one side by itself, so you've solved for b.

Answer 2

Crossmultiplying a/b=c/d becomes ad=bc Divide by a it's d=bc/a. Multiplying 2 times both sides of 5/2=1/2(b-c) it's 5=b-c Add c to both sides so 5+c=b. Hope you understand how this was done good luck with the rest of your homework. Thanks for the 2 points!

Answer 3

a/b=c/d
If you cross multiply, you get ad=bc
Divide by a and you get d=bc/a

5/2=1/2(b-c)
Multiply both sides by 2 to get rid of the 1/2 so you get 5=b-c
Add c to both sides and you get 5+c=b

Answer 4

a/b = c/d

ad = bc {multiply both sides by bd}

d = bc/a {divide both sides by a}


5/2 =1/2(b - c)

5 = (b - c) {multiply both sides by 2}

5 = b - c

c + 5 = b {add c to both sides}

Answer 5

"a/b=c/d", cross multiply so you get "ad=bc", move "a" to the other side so you end up with "d=bc/a"

"5/2=1/2(b-c)", distribute the 1/2 so you end up with "5/2=1/2b-1/2c", add 1/2c to both sides, now you have "5/2+1/2c=1/2b", now multiply both sides by 2 and you get "5+c=b"

Answer 6

Blah. I'm only doing this to get points.

You probably won't get this.

a/b = c/d
move the d over the other side by multiplying
da/b=c
multiply b over to other side
da=bc
move a over to the other side by dividing
d=bc/a


5/2=1/2(b-c)
move the ½ to the other side by dividing
5=b-c
move c over to the other side by adding
5 +c=b

Answer 7

5/2=1/2(b-c)
5/2=1/2b-1/2c
1/2b=5/2+1/2c
b=5/2 divided by 1/2 +c
b=5/4+c

Answer 8

You can take reciprocals across the equals to get
b/a=d/c and then multiply both sides by c.

multiply both sides by 2. Then add c to both sides.

Answer 9

a/b=c/d
da/b=c
da=bc
d=bc/a

5/2=1/2(b-c)
5/2=b/2-c/2
5+c/2=b/2
5+c=b
b=5+c