how do you work out #11

Question

anonymous · Answer

attachment

campbell_st · Answer

solve simultaneously

x + y = 26
3x + 2y = 60

x = 8, y = 18

anonymous · Answer

how did you get the x and y so quickly, how did you know 8 and 18?

campbell_st · Answer

well you have 2 equations 

double equation 1 and then subtract it from equation 2... this will eliminate y

      3x + 2y = 60
-    2x  + 2y = 52

subtracting each term   x = 8 is the solution... then sub into the equation x + y = 26.. and y has to be 18...

its called solving simultaneous equations...

anonymous · Answer

would you please show me your work?

anonymous · Answer

im trying to follow, sorry im new at this

campbell_st · Answer

let x be the 1st number and y the second... 

the question said the sum of the 2 numbers was 26

so x + y = 26

it also said 3 times the smaller plus 2 times the larger is 60

 3x + 2y = 60

then solve  as above

anonymous · Answer

can you always double the equation one and subtract it from the other?

anonymous · Answer

campbell? can you always double the equation one and subtract it from the other?

anonymous · Answer

you doubled it to get 2y so you could solve for y, right? I think I get it.

campbell_st · Answer

yes.. you choose an operation that allows you to eliminate a pronumeral

anonymous · Answer

in order to get rid of y you had to double everything in the second equation and then ....awesome