Question

2. How many solutions does this system have? 2x + y = 3, 6x = 9 – 3y

A) 1
B) None
C) Infinite
D) 2

Answer 1

2x + y = 3
6x = 9 - 3y
↓
2x + y = 3
6x + 3y = 9

3(2x + y = 3)
3(2x) + 3(y) = 3(3)
6x + 3y = 9

There is an infinite number of solutions in the system (the answer is C).

Answer 2

The system of equation has infinite solution.

C is correct.

Explanation:

We are given system of equation

2x + y = 3

6x = 9 – 3y

First we re-write the second equation in standard form

So, we add 3y both sides

6x+3y=9 ---------------- (2)

2x+y = 3----------------- (1)

Multiply equation 1 by 3

3(2x)+3y = 3(3)

6x+3y=9

Subtract new equation from 2nd equation

6x-6x + 3y-3y = 9-9

0=0

LHS=RHS

This is true statement. If statement is true then infinite number of many solution.

Hence, The system of equation has infinite solution.