Solving systems of equations

Question

How do you solve a system of equations using substitution?

How do you solve a system of equations by graphing?

Answer 1

consdier a specific example

y = 2x

x+ y = 9

substitute 2x for y in the 2nd equation

then

x +2x = 9

3x = 9

x = 9/3 = 3

x= 3

y =2(3) = 6

y = 6

or graph the 2 equations

where the 2 lines intersect is the solution

the point (3,6)