Solve these linear systems algebraically to find each point of intersection
a) x - y = -4
y = 2x - 3
b) y = x
3x - 10y = 14
2006-09-13 17:50:58 · 13 answers · asked by tenizgurl7 3 in Education & Reference ➔ Homework Help
a) y = x + 4. so substituting into the second part gets
x + 4 = 2x - 3 by solving this we get that x = 7. Plugging that back into the first equation gets y = 11. So, the point of intersection is
(7 , 11)
b) Substitute here to get 3x - 10x = 14. So x = -2. If y = x, y also equals -2. The point of intersection is
(-2 , -2)
2006-09-13 17:58:41 · answer #1 · answered by Eric J 1 · 0⤊ 0⤋
a) x - y = -4
y = 2x - 3
* x-(2x-3)=-4
x-2x+3=-4
-x=-4-3
-x=-7
x=7
*y=2x-3
= 2(7)-3
= 14-3
=11
b) y = x
3x - 10y = 14
* 3x-10x=14
-7x=14
x=-2
* y=x
y=-2
2006-09-14 01:09:29 · answer #2 · answered by Lisa S 1 · 0⤊ 0⤋
ok its been 10+ years since I have taken or used algebra but here it goes: A) x-(2x-3)=-4 = x-2x+3=-4 = -x=-7 = x=7
B) 3x-10x=14 = -7x=14 = -7x/-7 = 14/-7 = x = -2 or y = -2. Please tell me how I did. I think a missed a step in part B?
2006-09-14 01:03:40 · answer #3 · answered by fdmedic84 2 · 0⤊ 0⤋
x-(2x-3)=-4 then -x=-4-3 then -x=-7 therefore x = 7; y = 11 b) 3(y)-10y=14 then -7y=14 then y=-2 therefore x and y = -2
2006-09-14 00:58:42 · answer #4 · answered by Scout Finch 2 · 0⤊ 0⤋
a) x - y = -4
x = y - 4 (1)
y = 2x-3 (2)
subt. (2) into (1)
x = 2x - 3 - 4
2x - x = 4+3
x = 7
frm (2), y = 2 (7) - 3
y = 11
therefore, (x,y) = (7,11)
b) y = x (1)
3x - 10y = 14 (2)
subt (1) into (2)
3x - 10x = 14
-7x = 14
x = -2
since y = x,
y = -2
therefore (x,y) = (-2,-2)
2006-09-14 01:09:10 · answer #5 · answered by starrypolka 1 · 0⤊ 0⤋
b) x=-2, y=-2
3x-10y=14; 10y=3x-14
7y=-14; y=-2=x
a) x=7, y=11
x-y=-4; y=x+4
2x-3=y=x+4
x=7, y=11
2006-09-14 01:08:39 · answer #6 · answered by manchester 3 · 0⤊ 0⤋
b) x=-2, y=-2
3x-10y=14; 10y=3x-14
7y=-14; y=-2=x
a) x=7, y=11
x-y=-4; y=x+4
2x-3=y=x+4
x=7, y=11
2006-09-14 00:54:02 · answer #7 · answered by t_e_sumner 3 · 0⤊ 0⤋
A.
x-(2x+3)=-4
x-2x-3=-4
-x-3=-4
+3 +3
-x=-1
x=1
B.
3y-10y=14
-7y=14
/-7 /-7
y=-2
x=-2
those are the answers! algebra is so easy.
2006-09-14 01:04:17 · answer #8 · answered by BRiDGETTE 3 · 0⤊ 0⤋
find x and y coordinates
x - y = -4
- y = -4
y=4
(0,4)
x-0=4
x=4
(4,0)
very easy
y=x
3x - 10y =14
3x - 10x = 14
-7x = 14
x = -2
x = y
(-2, -2)
(-1, -1)
( 0 ,0)
(1, 1)
(2, 2)
2006-09-14 01:01:34 · answer #9 · answered by Anonymous · 0⤊ 0⤋
Rofl i learned that in grade 7 >;x
2006-09-14 00:53:40 · answer #10 · answered by alyssa! 3 · 0⤊ 0⤋