Question

i forgot how to solve systems of equations?
2a + b = 5
a - b = 1

Answer 1

These equations are perfectly set up for the elimination method. The first equation has a positive b, and the second equation has a negative b. So, add the two equations down, which will eliminate the b and let you solve for a

Answer 2

add them and solve for a.

Answer 3

so 3a - b = 6 then plug zero in as b to find a? answer choices are (-2,1) (2,1) (2,-1) (-2,-1)

Answer 4

still dont get it

Answer 5

you can add them vertically cuz b has opposite coefficient already

Answer 6

2a + b = 5
a - b = 1
------------
3a = 6

Answer 7

divide 3, you have a !

Answer 8

but the answer choices are (-2,1) (2,1) (2,-1) (-2,-1)

Answer 9

3a = 6

divide 3

a = 2

Answer 10

a = 2 -----------------(1)

Answer 11

plug in a = 2 in your second equation, and solve b

your second equaiton :-
a - b = 1

put a = 2
2 - b = 1

solve,
b = 1 -----------------------------(2)

Answer 12

so the solution (a, b) = (2, 1)

Answer 13

a = 2

Answer 14

does that make some sense

Answer 15

wen i plug it in i get b = 3 which isn't one of the points

Answer 16

how did u get b = 3 ? :)

Answer 17

please show your steps, so we can see whats happening :)

Answer 18

a - b = 1
2- b = 1 add 2 on both sides b = 3

Answer 19

^ you need to add -2 both sides

Answer 20

a - b = 1
2- b = 1 add -2 on both sides -b = -1

Answer 21

then multiply -1 both sides, b = 1

Answer 22

oh I get it now. Thanx alot :)

Answer 23

good :) you wud have noticed that when u added 2 both sides for 2-b=1, you should get 4-b = 3, you should NOT get b = 3