Question

Solve the following system of
equations using the elimination
method.
,
(1 point)
0.1x + 0.3y = 0.9
0.1x − 0.3y = 0.2
(− , )
7
6
11
2
There is no solution
( , − )
11
2
7
6
( , )

Answer 1

Add the two equations to eliminate y:
0.1x+0.3y = 0.9
0.1x−0.3y = 0.2
---------------- +
0.2x = 1.1 ⇒ x = 1.1/0.2 = 11/2.

Substitute x into the first equation:
0.1(11/2) + 0.3y = 0.9 ⇒ 0.55 + 0.3y = 0.9 ⇒ 0.3y = 0.35 ⇒ y = 0.35/0.3 = 7/6.

Solution: (x, y) = (11/2, 7/6).