Do the ratios 3/9 and 4/12 form a proportion?

yes

Step-by-step explanation: when we’re asked to determine whether two ratios form a proportion, what we’re really being asked to do is determine whether the two ratios are equal because if the ratios are equal, we know they form a proportion.

So in this problem, we need to determine whether 3/9 = 4/12.

The easiest way to determine whether 3/9 = 4/12 is to use cross-products.

If the cross-products are equal, then the ratios are equal.

The cross-products for these two ratios are (3)(12) and (9)(4).

Are these products equal?

(3)(12) is 36 and (9)(4) is 36.

Since 36 = 36, we can see that the cross-products

are equal which means that the ratios are equal.

Since the ratios are equal, they do form a proportion.

20%

step-by-step explanation:

step-by-step explanation: given equation a = h(b 1+b 2)

also we are given values of a, h and b 1 as :

a = 16, h = 4, and b 1 = 3.

in order to solve it for b 2, we need to plug the given values of   a, h and b 1 .

therefore, plugging values of   a, h and b 1   in given equation, we get

16 = 4( 3 + b 2)

first dividing both sides by 4, we get

4 = 3 + b 2

subtracting 3 from both sides, we get

4 -3 = 3 -3 + b 2

1 = b 2.