Question

Solve the system of linear equations by graphing. Round the solution to the nearest tenth as needed.

y + 2.3 = 0.45x

–2y = 4.2x – 7.8

(2.4, –1.2)
(–1, 2.5)
no solution
infinitely many solutions

Answer 1

Solve for y from each equation:

1) y = 0.45x − 2.3
2) −2y = 4.2x − 7.8 → y = −2.1x + 3.9

Set equal: 0.45x − 2.3 = −2.1x + 3.9
2.55x = 6.2 → x = 6.2/2.55 ≈ 2.4

y = 0.45(2.4314) − 2.3 ≈ −1.2

Solution (rounded to the nearest tenth): (2.4, −1.2).