Question

Find the unknown number in the proportion
x=___

Answer 1

ANSWER: X=20

Step-by-step explanation:

X 28
— = —
45 63

to figure this out, use cross multiplication.

this means you multiply 63 • X = 63X
then, multiply 45 • 28 = 1260

now you have 63X=1260
the next step is to divide both sides by 63


63X = 1260
—— ——- ————> X=20
63 63

Answer 2

x = 20

Step-by-step explanation:

To solve this, you cross multiply. That means you multiply 45 and 28, and x and 63.

45(28) = 63x (multiply 45 and 28)

1260 = 63x (divide both sides by 63)

20 = x

We can check this by simplifying both fractions, and seeing if they are equivalent.

`(28)/(63)` ÷
`(7)/(7)` =
`(4)/(9)`

`(20)/(45)` ÷
`(5)/(5)` =
`(4)/(9)`

As
`(4)/(9) = (4)/(9)`, x = 20 is correct.

You also could've simplified before even solving, and instead solved:

`(x)/(45) = (4)/(9)` as
`(28)/(36)` simplifies to
`(4)/(9)`.

Then, you would've gotten:

45(4) = 9x (multiply 45 and 4)

180 = 9x (divide both sides by 9)

20 = x

Either way, you'd still get the same answer; Smaller numbers are just easier to work with.