Question

Carrie solved = by cross multiplying to get 4x = 6 and then divided both sides by 4. She got x = which reduced to x = . Is there a faster way to solve this problem?

Answer 1

Ok, when we have an equality, like:

A = B

That says that A is the same as B.

Then if a multiply, divide, add or subtract (or do a lot of other operations) in both sides of the equality, the equality does not change.

I suppose that we start with something like:

(4/3)*x = 2

(i will work with this, because you did not post the actual equations)

the thing that Carrie did is:

She multiplies both sides by 3, and get:

3*(4/3)*x = 2*3

4*x = 6

Now she divides bot sides by 4

4*x/4 = 6/4

x = 6/4 = 3/2.

Now, a simpler step is considerin (4/3) as a number A, then we have:

A*x = 2

Now we divide both sides by A.

A*x/A = 2/A

x = 2/A

and we have A = (4/3) then 1/A = (3/4)

x = 2*(3/4) = 3/2