MATH HELP!!!!!! PROPORTIONS!!!!!! EXPLAIN IF POSSIBLE!!!

Solve this proportion:
4/16 = s/8

Solve this proportion:
3/6 = 7/d


Tell whether the two ratios form a proportion. Explain.
9/24 and 15/40

Tell whether the two ratios form a proportion. Explain.
20/32 and 12/20

Solve.
x – 2 1/3 = - 4 4/15

Solve.
3 6/7x = 2 1/4
????? im not sure if im doing ... well any of these the correct way???

Hi:

4/16 = s/8 - original equation

4*8= 16s - cross multiplication

32 = 16s - multiplication 4*8

1/16 * 32 = 1/16 * 16s - Multiplying the reciprocal of a coefficient to both sides of the equation to solve for s

32/16 = s - Multiplication

2 = s - Division

Proof or check

4/16 = s/8 - original equation

4/16 = 2/8 - plugging s with 2

1/4 = 1/4 - Division

it checks and equals

Number 2 :

3/6 = 7/d - original equation

6*7= 3d - Cross Multiplication

42 = 3d - Multiplication of 6 and 7

1/3 *42 = 3d* 1/3 - Multiplying the reciprocal of a coefficient to both sides of the equation to solve for d

42/ 3 = d - Multiplication

14 = d - Division

Proof or check

3/6 = 7/d - original equation

3/6 = 7/14 - plugging d with 14

1/2 = 1/2 - Division

it checks and equals

Number 3

Given :

9/24 and 15/40

whether the two ratios form a proportion and explain why?

since proportion are two ratio that equal each other ( reason: Definition of a proportion) So

le see if

9/24 = 15/40

two ways to do this

1) reduce both fraction down to lowest common fractions

2) cross multiply it and divide it out

I will do this by # 1:


9/24 = 3/8 - reason: ( (9/3 = 3 )/ (24/3 = 8 ) = 3/8

15/40 = 3/8 reason : ( 15/5 = 3 ) / ( 40 /5 = 8 ) = 3/8

so

does 3/8 = 3/8

yes it does - So it is a proportion by the Definition of a proportion