Kyla used 550 grams of wool to knit a sweater, a hat, and a scarf. for the hat she used 5 times less wool than the sweater and 5 grams more than the scarf. how much did each item require.

This is the concept of algebra, to calculate the proportion of wool in each item we proceed as follows;
Let the amount of wool used for hat be x
amount of wool in sweater will be 5x
the amount of wool used in scarf will be x-5
 therefore the total amount of wool will be:
x+5x+(x-5)=550
x+5x+x-5=550
7x-5=550
7x=550+5
7x=555
hence;
x=555/7
x=79
the amount used in hat x=79g
amount used in sweater 5x=395g
amount used in scarf=79-5=74g

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post