At the bank of a river, by measurement, a = 9 ft., b = 15 ft., c = 12 ft., and d = 7 ft. How long is x?

x is 20

Step-by-step explanation:

This is ratio

a : c = b : x and d : unknown

a : c = 9 : 12 = 3 : 4 which is 9/12

b : x = 15 : x which is 15 / x

So the proportion will be :

3/4 = 15/x

So Cross multiplying

3x = 90

Divide both side by 3

x = 90/3

x = 20

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.

i don't see any steps below, sweetheart