### Home > PC > Chapter 12 > Lesson 12.2.1 > Problem 12-42

12-42.

Use substitution.

Use the distributive property, then combine like terms.

2**i** + 4**j** + *t*(−**i** −7**j**)

= 2**i** + 4**j** −*t***i** −7*t***j**

= 2**i** −*t***i** + 4**j** −7*t***j**

If (0, 10) is on the line, then 0**i** + 10**j** is possible.

(2 − *t*)**i** + (4 − 7*t*)**j** = 0**i** + 10**j**

2 − *t* = 0 4 − 7*t* = 10

Does *t* have the same value in both equations?

If it is on the line, then it should.