Answer :
x = reels
y = rods
so
3x + 5y = 309
6x + 2y = 282
let's use equation 2 and get the y's on a side by themself by subtracting 6x from both sides
6x + 2y - 6x = 282 - 6x
becomes
2y = 282 - 6x
now divied both sides by 2
y = (282 - 6x) / 2
y = 141 - 3x
now stick that y value into the first equation
3x + 5y = 309
becomes
3x + 5(141 - 3x) = 309
multiply it out
3x + 705 - 15x = 309
-12x = 309 - 705
-12x = -396
x = 33
cost of each reel = 33
now substitute 33 for x into equation 1 or equation 2 (it doesn't matter which) to find out the value of each rod using equation 1
3x + 5y = 309
3(33) + 5y = 309
99 - 309 = -5y
-210 = -5y
y = 42
y = rods
so
3x + 5y = 309
6x + 2y = 282
let's use equation 2 and get the y's on a side by themself by subtracting 6x from both sides
6x + 2y - 6x = 282 - 6x
becomes
2y = 282 - 6x
now divied both sides by 2
y = (282 - 6x) / 2
y = 141 - 3x
now stick that y value into the first equation
3x + 5y = 309
becomes
3x + 5(141 - 3x) = 309
multiply it out
3x + 705 - 15x = 309
-12x = 309 - 705
-12x = -396
x = 33
cost of each reel = 33
now substitute 33 for x into equation 1 or equation 2 (it doesn't matter which) to find out the value of each rod using equation 1
3x + 5y = 309
3(33) + 5y = 309
99 - 309 = -5y
-210 = -5y
y = 42