Question

Select all the systems of equations that have exactly one solution.
A. {y = 3x + 1 y =− 3x + 7
B. {y = 3x + 1 y = x + 1
C. {y = 3x + 1 y = 3x + 7
D. {x + y = 10 x + y = 12

Answer 1

Step-by-step explanation:

The line y=3x+5 is a linear equation in two variables.

For every value of x, there is a unique value of y

Put x=0⇒y=5

Hence, (0,5) is a solution

Put x=1,⇒y=8

Hence, (1,8) is a solution .

Put x=−1,⇒y=2

Hence, (−1,2) is a solution .

So ,on keeping different values of x, we get different values of y.

Hence, infinitely many solutions are possible.

Answer 2

I don't have an answer but one thing that my teacher said that can help is that you can eliminate all of the equations that have no solutions.