Question

Someone Please Help!
Solve a system of linear equations using substitution, elimination OR substitution!
3x - y = -137
y = 2x + 99

Answer 1

what is x?

Answer 2

3x - y = -137 ...........(1)
y = 2x + 99 ..............(2)
substitute (2) into (1)

3x -(2x+99) = -137
try solving it now

Answer 3

good reply!

Answer 4

put your second equation in first one
3x- ( 2x+99) = -137
find x now.

Answer 5

i got y = 23 for substituting. Now i have 2 more equations that i have to find for graphing and eliminating, can someone help me witht hose 2??

Answer 6

i can try

Answer 7

what r they?

Answer 8

THANK YOUU!!
2.) 2x + y = -1
x + 4y = -10
3.) 2x + y = -1
3x - y = 16
And i have to solve it by substituting and the other by graphing:\

Answer 9

sorry, i meant *eliminating* and graphing!

Answer 10

ok mmmmmmmmhhhhhhhhhhhhhhhhhhh... i am not sure how much help that i will be since i am 10 years old :/

Answer 11

:)

Answer 12

Oh myyyy haha, at least you know more than me. I'm 17! Your smart. But if you can just try? or start me off and i can try to figure out the rest by myself

Answer 13

ok i will try... gtg sorry :((

Answer 14

kay, bye. thanks tho

Answer 15

for 2) by elimination
2x+y=-1...........(1)
x+4y = -10.......(2)

(2) x 2
2x+8y = -20......(3)

(3) -(1)
7y = -19
k solve it now

Answer 16

Wait, 2x + 8y = -20, i can't solve it no more, can i ? idk, i'm confused! how do you get (3) - (1) ?

Answer 17

(3) - (1) as in equation (3) - equation(1) to eliminate the 2x which is common in both equations

Answer 18

basically i manipulate (2) so that the x component looks like (1). I then label the manipulated (1) as a new equation (3). (3) and (1) have 2x. so if i take (3) - (1) i will eliminate the 2x and get left with 7y = -19

Answer 19

2x + y = -1......(1)
2x + 8y = -20...(3)

(3) - (1)

2x - 2x +8y - y = -20 - (-1)
7y = -19

Answer 20

Ohh! okay okay, i understand.. so y = -2.714 ?

Answer 21

@irkiz thank you anyways