Show How To Solve By Substitution Method 8x+5y=184,x-y=3 Please Break Down?

3 Answers

Anonymous Profile
Anonymous answered
8x+5y=184 equ 1
x- y= 3 equ 2
from equ 2 make x the subject
x - y = 3
x= 3+y equ 3
subtittude equ 3 into equ 1
8(3 + y ) +5y = 184
24+8y+5y =184
collect like terms
8y + 5y = 184 - 24
13y = 160divide both sides by 13
therefor y = 12.3
subtitude y = 12.3 into equ 3
x = 3+y
x = 3 + 12.3
x=15.3
y = 12.3 while x = 15.3
Oddman Profile
Oddman answered
Solve the second equation for x by adding y to both sides.  X - y = 3  x = 3 + y Now use this expression for x in the first equation and solve for y.  8x + 5y = 184  8(3 + y) + 5y = 184    (where x was we now have 3+y. This is the substitution.)  24 + 8y + 5y = 184    (use the distributive property to eliminate parentheses)  13y = 160    (subtract 24 from both sides)  y = 160/13 = 12 4/13  x = 3 + y = 3 + 12 4/13 = 15 4/13
(x, y) = (15 4/13, 12 4/13)
Check  8x + 5y = 184  8(15 4/13) + 5(12 4/13) = 184  120 + 32/13 + 60 + 20/13 = 184  180 + 52/13 = 184  180 + 4 = 184    (yes, first equation checks)    x - y = 3  15 4/13 - 12 4/13 = 3    (yes. We know this because we used this second equation to get x.)

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