Using the substitution method, what is the solution set for the system ?
3x+y=1
y=5x-4
2006-10-11 10:53:09 · 8 answers · asked by Korey's Mamacita 1 in Science & Mathematics ➔ Mathematics
Hi dear ;
3x+y=1
y=5x-4
Step 1
Fill the value of ' y ' in to the first function ;
3x + ( 5x - 4) = 1
3x + 5x - 4 = 1
8x = 4 + 1
2x = 5
x = 5 / 8
Step 2
Now fill the value of ' x ' in to one of the functions
3x+y=1
3*( 5/8) + y = 1
15/8 + y = 1
y = 1 - 15/8
y = - 7/8
The Result is
x = + 5/8
y = - 7/8
Good Luck
2006-10-11 11:50:46 · answer #1 · answered by sweetie 5 · 7⤊ 1⤋
3 x + y = 1
y = 5 x -4
Substitue the second equation into the first as below
3 x + 5x -4 = 1
Then combine and solve
8 x - 4 = 1
8 x = 5
x = 5/8
Now plug in 5/8 for x into either equation.
3 (5/8) + y = 1
15/8 + y = 1
1 7/ 8 + y = 1
y = 7/8
so your answer would be (5/8, 7/8)
2006-10-11 17:57:35 · answer #2 · answered by danjlil_43515 4 · 0⤊ 1⤋
you substitute the second equation into the first
3x+5x-4=1
8x=5
x=5/8
so y=5(5/8)-4
=(25-32)/8
= -7/8
2006-10-11 17:57:08 · answer #3 · answered by locuaz 7 · 1⤊ 0⤋
Substitute y=5x-4 into the first equation and get
3x+(5x-4)=1
or
8x-4=1
or
8x=5
so x=5/8. Now subsitute this x into either equation to find y.
2006-10-11 17:55:06 · answer #4 · answered by James L 5 · 1⤊ 1⤋
3x+y=1
y=5x-4
3x+5x-4=1 (subsitute y for 5x-4)
8x-4=1 (add together common things)
8x=5 (add 4 to each side it cancels out)
x=0.625 (divede by 8 on each side)
subsitute what x is on each side
y= 5 (times) 0.625 - 4
y= 3.125-4
y= -0.875
2006-10-11 18:07:02 · answer #5 · answered by Michelle M 1 · 0⤊ 0⤋
3x + (5x -4) = 1
3x + 5x -4 = 1
8x -4 = 1
8x = 5
x = 5/8
2006-10-11 17:56:13 · answer #6 · answered by Anonymous · 1⤊ 1⤋
3x+y=1
y=5x-4
3x+5x-4=1
8x-4=1
8x-4+4=8+4
8x=12
8x/8=12/8
x=12/8
2006-10-11 17:56:38 · answer #7 · answered by Anonymous 2 · 0⤊ 2⤋
C'mon that one is easy you should really do your own homework ya know
2006-10-11 17:55:43 · answer #8 · answered by curious caucasian 3 · 0⤊ 2⤋