Methods:
1) Graphing
2) Substitution
3) Elimination
-Combine the two equations to eliminate/cancel a variable. you want the coefficients of 1 of the variables to be opposites.
ex. Solve: ex. Solve:
2x+5y=11
4x-5y=7 6x=18
6 6
x=3
(now plug 3 in for x)
6+5y=11
-6 -6 5y=5
5 5
y=1
(write as ordered pair)
(3,1)
ex. Solve:
5x-7y=-26
11x-7y=10(divide them all by negative 1 to make 7y opposites)
-11x+7y=-10 -6x=-36
-6 -6
x=6
30-7y= -26
-30 -30 -7y= -56
-7 -7
y=8
(6,8) --> REMEMBER : ORDERED PAIRS.
ex. Solve:
4a+b=5
-6a-b=-6 -2a= -1
-2 -2
a=1/2
(now plug 1/2 in for a)
2-b=5
-2 -2
b=3
(1/2,3)
Methods:
1) Graphing
2) Substitution
3) Elimination
-Combine the two equations to eliminate/cancel a variable.
you want the coefficients of 1 of the variables to be opposites.
ex. Solve: ex. Solve:
2x+5y=11
4x-5y=7
6x=18
6 6
x=3
(now plug 3 in for x)
6+5y=11
-6 -6
5y=5
5 5
y=1
(write as ordered pair)
(3,1)
ex. Solve:
5x-7y=-26
11x-7y=10(divide them all by negative 1 to make 7y opposites)
-11x+7y=-10
-6x=-36
-6 -6
x=6
30-7y= -26
-30 -30
-7y= -56
-7 -7
y=8
(6,8) --> REMEMBER : ORDERED PAIRS.
ex. Solve:
4a+b=5
-6a-b=-6
-2a= -1
-2 -2
a=1/2
(now plug 1/2 in for a)
2-b=5
-2 -2
b=3
(1/2,3)