Answer:
first one is not. parallel second one is not and the third one is
Answer: 1045 cm of red ribbon and 1045 cm of yellow ribbon
<u>Step-by-step explanation:</u>
Let R represent the amount red ribbon and Y represent the amouont of yellow ribbon.
- bought the same lengths of red and yellow: R = Y
- after used 286 of red, yellow is 5 times the remaining red; 5(R - 836) = Y
Use substitution method to solve:
5(R - 836) = R
5R - 4180 = R <em>distributed 5 on the left side</em>
4R - 4180 = 0 <em>subtracted R from both sides</em>
4R = 4180 <em>added 4180 to both sides</em>
R = 1045 <em>divided both sides by 4</em>
572 rounded to the nearest 10 is 570 and 572 rounded to nearest 100 is 600.
area = pi X radius squared
so area = 3.14 x 124^2
= 3.14 x 15376 = 48,280.64 square centimeters.
and 
use the second expression to calculate the left-hand side of the first equation:
Add 10 to both sides if this equation to get
and divide both sides by 2
this proves that x = 17, give the two initial equations
