How do you answer a direct proportion?

Answer 1

this is the question:

A is directly proportional to B²

When A=50, B=10

a) Find an equation connecting A and B.

the formula to start answering this question is

A (direct proportion sign) B²

A=K*B²

then you have to fill in the numbers for A and B² so you get this:

50=K*10²

50=K*100

so then you have to find out K so you have to do 50/100 which is 0.5 so K=0.5. THen you have to write the equation in full to get the full marks so it's just: A=0.5*B².

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then you will have to put your formula in action so say that the question was:

b) find the value of B when A is 72

you would have to substitute the numbers is so that its : 72(A)=0.5(K)*B

so then you would have to divide 72 by 0.5 to get the answer which is 144. Then you have to remember to SQUARE ROOT 144 to get B becasue you have only got B², not just B. so the final answer is ... 12!

i hope this helped x