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1 vote
HELP ASAP!! Use cross products to determine which are valid proportions.

Proportion
Not a Proportion
2/3 and 9/12
3/8 and 6/141
18/8 and 9/4
775 and 27/20
4/7 and 10/17.5

2 Answers

5 votes

Answer:

Proportions:

18/8 and 9/4

4/7 and 10/17.5

Everything else is Not a Proportion

Correct on edge as well ;P

Explanation:

User Ladi
by
7.2k points
6 votes

Answer:

Proportions:

18/8 and 9/4

4/7 and 10/17.5

Everything else is not a proportion

Explanation:

To find if two fractions are a proportion, we need to set each up as a fraction. Then, we multiply both diagonal values. If we get the same value, they are proportionate.


(2)/(3) and
(9)/(12):


12\cdot 2= 24\\\\9 \cdot 3 = 27\\\\24 \\eq 27

So these aren't proportionate.


(3)/(8) and
(6)/(141):


141\cdot 3 = 423\\\\8 \cdot 6 = 48\\\\48 \\eq 423

So these aren't proportionate either.


(18)/(8) and
(9)/(4):


18 \cdot 4 = 72\\\\9 \cdot 8 = 72\\\\72 = 72

So this is proportionate.


(775)/(1) (since 775 is just that over 1) and
(27)/(20):


775 \cdot 20 = 15500\\\\1 \cdot 27 = 27\\\\27 \\eq 15500

So this isn't proportionate.


(4)/(7) and
(10)/(17.5)


4\cdot 17.5 = 70\\\\7 \cdot 10 = 70\\\\70 = 70

So this is proportionate.

Hope this helped!

User Andyzinsser
by
7.5k points