How do you solve the proportion $7:5 = x:20$ ?

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Answer 1 · 2015-04-29T15:20:10

$7:5 -=(7xx4):(5xx4) -= 28:20$

that
$7:5 = x:20$
$rarr x= 28$

Alternately we could rewrite the ratios as fractions:
$7/5 = x/20$

Multiplying both sides by $20$
$x = (7xx20)/5 = 7xx4 = 28$

How do you solve the proportion 7:5 = x:207:5 = x:20?