Help me solve this equation using susbtitution....?
2007-09-27 01:40:02 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
3x+6y=48
-5x+6y=32
[(3x +6y)]- [-5x+6y] = 48-32
8x=16
x=2
2x3 + 6y = 48
6y=42
y=7
so X=2, y=7
2007-09-27 01:51:05 · answer #1 · answered by Anonymous · 0⤊ 0⤋
3x + 6y = 48 ----------eqn 1
-5x + 6y = 32 ---------- eqn 2
from eqn 2
6y = 32 + 5x
y = (32 + 5x)/6 ----------- eqn 3
sustitute eqn 3 into eqn 1
3x + 6(32 + 5x)/6 = 48
8x + 32 = 48
8x = 48 - 32
8x = 16
x = 16/8
x = 2
put the value of x into eqn 2
-5(2) + 6y = 32
-10 + 6y = 32
6y = 32 + 10
6y = 42
y = 42/6
y = 7
ans: x = 2, y = 7
2007-09-27 08:57:19 · answer #2 · answered by Ayo James 1 · 0⤊ 0⤋
3x +6y =48 ..........1
-5x+6y=32 ..........2
from (1) we get 6y = 48-3x ......3
substitute (3) in (2) -5x +(48-3x) = 32
-5x-3x=32-48
-8x = -16
x=2
substitute x=2 in (1) 3(2) +6y = 48
6y=48 -6
6y =42
y= 7
2007-09-27 08:54:51 · answer #3 · answered by billako 6 · 0⤊ 0⤋
3x+6y= 48 -5x+6y= 32
Subtract 2nd eqn. from 1st to get
8x = 16 and x = 2
Putting x = 2 in 1st eqn., y = 7
2007-09-27 08:47:25 · answer #4 · answered by Madhukar 7 · 0⤊ 0⤋
3x+6y=48
dividing by three u get x+2y=16
therefore x=16-2y
-5x+6y=32
substituting for x in this equation
-5(16-2y)+6y=32
-80+10y+6y=32
16y=112
y=7
x=16-2y=16-2*7
x=2
2007-09-27 08:46:38 · answer #5 · answered by priyaprayag1989 1 · 1⤊ 0⤋
3x+6y=48
-5x+6y=32
3x=48
-5x=32
8x=16
x=16/8
x=2
3x+6y=48
3*2+6y=48
6y=48-6
6y=42
y =42/6
y= 7
x=2, y=7
2007-09-27 08:46:27 · answer #6 · answered by Flamezz 5 · 0⤊ 1⤋
subtract 2nd eq from eq 1
3x+6y=48
5x-6y=-32
________
8x=16
x=2 ----------- (i)
Put this value in eq 1
3(2) +6y = 48
6y=48-6
y=42/6
y=7 -------------- (ii)
x=2 / y =7
2007-09-27 08:46:34 · answer #7 · answered by usman 3 · 0⤊ 0⤋
15x + 30y = 240
-15x + 18y = 96-----ADD
48y = 336
y = 7
3x + 42 = 48
3x = 6
x = 2
x = 2 , y = 7
2007-09-29 10:22:13 · answer #8 · answered by Como 7 · 0⤊ 0⤋
awww. ur not stupid.... x=7 and y=2.. hope thats rite. first u multiply the second equation by a neg 1 and then just subtract them... u'll get the 'y' and then plug y back into the 1st equation and u should get 7. hope i helped. good luck!! ;)
2007-09-27 08:43:24 · answer #9 · answered by samantha 5 · 0⤊ 1⤋