What must be added to each of the numbers 5, 9, 7, 12 to get the numbers
which are in proportion?
Answers
Answer:
ANSWER----> 3
Step-by-step explanation:
let the number be x
then the numbers will be
5+x,9+x,7+x,12+x
according to proportion
5+x:9x+7::7+x:12+x
= (5+x)/(9+x) = (7+x)/(12+x)
=(5+x)(12+x) = (9+x)(7+x)
Do cross multiplication
=(60+5x+12x+x square) = (63+9x+7x+x square)
=(60+17x+x square) = (63+16x+x square)
= 60+17x+x square = 63+16x+x square ( x square and x square gets cancelled )
= 60+17x = 63+16x
= 17x - 16x = 63 - 60
= x = 3 Substitution The numbers are: 5+x , 9+x , 7+x and 12+x
5+3 , 9+3 , 7+3 , 12+3
8:12::10:15
Product of extremes = Product of means
8*15 = 12*10
120 = 120
3 should be added to each of the numbers 5 , 9 , 7 and 12 to get the numbers which are in proportion