Question

a+9b=20 a+3b=2 how would you use elimination method for this

Answer 1

Hint: Multiply the second equation by -3

Answer 2

a+9b=20
a+3b=2

try to eliminate a , we have 6b=18
so b is ?

Answer 3

You could also multiply one of the equation by -1 and then solve for b.

Answer 4

I am confused

Answer 5

a+9b=20
a+3b=2

(a+9b=20)*(-1)
a+3b=2

-a-9b=-20
a+3b=2

Add the two equations together and you'll get
-6b=-18
b=(-18/-6)
b=3

Plug b=3 back into one of the equations.
a+3b=2
a+3(3)=2

Solve for a
a = 2-3(3)
a = 2-9
a = -7