Question

Using elimination to solve the system 2x + y = 8 and x + y = 4, which of the following could be the first step?
A. 2x + y = 8--------> 2x + y = 8
(x + y = 4)(-1)---> -x - y = -4
B. 2x + (4 - x) = 8
C. 2x + y = x + y
D. 3x + 2y = 12
E. x = 4

Answer 1

I said it was A...

Answer 2

B

Answer 3

A-B

Answer 4

What does that mean?

Answer 5

basically you take away the 2nd equation from the first equation

Answer 6

to eliminate y

Answer 7

then find x

Answer 8

So its E?

Answer 9

yep

Answer 10

x=4

Answer 11

what level question is this?

Answer 12

What do you mean?

Answer 13

what year? gcse year 9, 10?

Answer 14

9

Answer 15

oh ok thats good

Answer 16

Why?

Answer 17

i just wanted to know... I remember doing that question for a gcse paper long time ago

Answer 18

2x+y=8
(x+y=4) *-1

2x+y=8
-x-y=-4
The FIRST step would be A

Answer 19

Wait.. E or A?

Answer 20

You can't get to x=4 using elimination without first doing step A or an equivalent step

Answer 21

You could also multiply the 1st equation by -1, but that's not an option