Answer:
I'll setup the problem and you can do the calculations
Step-by-step explanation:
Total length of straw - L
Length of piece 1 - x
Length of piece 2 - y
Length of piece 3 - z
What's given and the answer to (i)
y = x - 3
z = 2x
(ii) L = x + y + z = x + x - 3 + 2x
L = 4x-3
(iii) x = (21+3)/4 = 24/4
leaving you to calculate x
then substitute x into expressions for y & z above and you will have the answer
comment if you have questions
9(n+3)=7n-3
1) distribute 9 into (n+3)
9n+27=7n-3
2) subtract 7n on both sides
2n+27=-3
3) subtract 27 on both sides
2n=-30
4) divide by 2
n=-15
the answer is b Im pretty sure