My father taught me a method that I call, 'throwing some thing over the wall'. There is a sample equation for the first picture that shows you how it works. It's a great way to help isolate the variable and I hope that it works for you. The second picture contains the answers I got through the use of this method. I'm sorry for the messy handwriting; I was on a bus.
Answer:
7x+2z+16
Step-by-step explanation:
find like terms
7 9
add them
7+9=16
7x+2z+16
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
9 is 22.5% of 40 if that's the question.
