solving simultaneous eqns using substitution: 10x-3y=19,x+2y

[amber_xoxo]

i have tried to start the solution however i am unsure as to where to go from here

10x - 3y = 19 equation 1)
x + 2y = 18 equation 2)

from equation 2) make x the subject

x = 18 - 2y

substitute this into equation 1)

10(18 - 2y) - 3y = 19
180 - 20y - 3y = 19
180 - 17 y = 19

 

[Loren]

Re: solving simaltainious equaitions using substitution

10x - 3y = 19 equation 1)
x + 2y = 18 equation 2)

from equation 2) make x the subject

x = 18 - 2y

substitute this into equation 1)

10(18 - 2y) - 3y = 19
180 - 20y - 3y = 19
180 - 17y = 19 <<< -20y - 3y = ???

Make correction in this line then go ahead and make y the subject (solve for y). Once you have that value (it will be an integer in this case) plug it back into line 3 or either of the original equations and solve for x. Be sure to check your solution by substituting both values back into both of the original equations and see if they tell the truth.