For example i will chose equation 2x+y=6 and solve for y by bringing 2x to other side and y= -2x+6. Now we will use the first equation 3x-y=15 and substitute the value of y that we obtained from other equation:3x-(-2x+6)=15 and we will simplify to have3x+2x-6=155x-6=155x=21x=21/5 so after we have x than we need to find y, so y=-2x+6 hence y=-2(21/5)+6y=-41/5+6y=-41/5+30/5y= - 11/5-1. Substitution method:From first eqn x=(7-2y)sub into second eqn (7-2y)-y=-512=3yy=4From second eqn x=y-5=4-5=-11. Elimination method:first equation subtract second equation to eliminate xs givesx-x+2y+y=7+53y=12y=42. Elimination method:(add equations together to eliminate y)3x+2x-y+y=15+65x=21x=21/5From first eqn y=3x-15=3(21/5)-15=-12/52.......
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3x=-3 that means x=-1 and then we need to put the x in one of the equations to find y. so i will put in the first one:
-1+2y=7
2y=8
y=4
that was elimination method.
Now elimination method for question 2:
first you chose equation and solve for one variable. For example i will chose equation 2x+y=6 and solve for y by bringing 2x to other side and y= -2x+6. Now we will use the first equation 3x-y=15 and substitute the value of y that we obtained from other equation:
3x-(-2x+6)=15 and we will simplify to have
3x+2x-6=15
5x-6=15
5x=21
x=21/5 so after we have x than we need to find y, so y=-2x+6 hence
y=-2(21/5)+6
y=-41/5+6
y=-41/5+30/5
y= - 11/5
1. Substitution method:
From first eqn x=(7-2y)
sub into second eqn (7-2y)-y=-5
12=3y
y=4
From second eqn x=y-5=4-5=-1
1. Elimination method:first equation subtract second equation to eliminate x's gives
x-x+2y+y=7+5
3y=12
y=4
2. Elimination method:
(add equations together to eliminate y)
3x+2x-y+y=15+6
5x=21
x=21/5
From first eqn y=3x-15=3(21/5)-15=-12/5
2. Substitution method:
From first eqn y=3x-15
Sub into second eqn 2x+3x-15=6
5x=21
x=21/5
