Question

2x + 5y = 13
-x + 4y = 13
solve by elimination

Answer 1

Answer:

i think x=-1 and y=3. ....

Answer 2

Answer:

x = -1 ,  y = 3

Step-by-step explanation:

2x+5y = 13

-x+4y = 13

Decide whether to add or subtract the two equations by using Different Add Same Subtract (DASS)   or in case below as its SUBTRACT

i apply (SDSS).  

We subtract 5y as this is easier equation either positive prioritises or if both positive then easier number becomes priory.

   

Results to SDSS  before substituting Y if 5y etc was subtracted

2x+5y = 13             Subtract -5  

2x+5y -5y = 13 -5y  

2x= 13 - 5y             then Divide by 2

2x / 2 = 13/2 - 5y/2          Show then

x = 13 - 5y  / 2  + 4y = 13     Simplify

simplify  13 - 13y  / 2   as   y = 3  

as 13/2 = 6.5 and 2.5 +4 = 6.5

y = 3

Substitute y = 3

13-5y )3) / 2

13-5 (3)  / 2

BODMAS Brackets first Multiplying only for y substitute 5y = 5 x 3

-5 (3) = 15

13-15 = -2

-2/2 = -1

x = -1