Question

Look at this system of equations.
7x+3y=-6
7x+3y=5
Which one of the following best describes the solution?
A: All real numbers
B: x=0, y=0
C: There is no solution
D: There are an infinite number of solutions.

Answer 1

yes, I am looking at it...........

Answer 2

which one do you think it is and I will try to help you understand which is the solution and why

Answer 3

One second @precal

Answer 4

ok leaving in 5 minutes,.........

Answer 5

Well it cannot be B

Answer 6

it can not be B because if you sub x=0 and y=0
you get 0=-6 and 0=5 ok that is correct

Answer 7

what else do you know?

Answer 8

it cannot be A (a real number) as the y intercept will be negative

Answer 9

or a decimal

Answer 10

in the 1st system of equations

Answer 11

y intercept does not tell us that it is all real numbers

Answer 12

how do you solve systems of equations?

Answer 13

Simplifying and graphing

Answer 14

graphing is not always a good way to solve systems, what if you do not know how to graph an equation

Answer 15

but graphing does tell us about the solutions

Answer 16

You can do it algebracially.

Answer 17

Using elimination?

Answer 18

which method algebraically do you use? substitution, elimination

Answer 19

yes, elimination works for all
you have it set up for elimination
so try to eliminate x or y, your choice, what number do you multiply to equation one or equation two

Answer 20

yes -1

Answer 21

Can i multiply the first equation by -1?

Answer 22

now add that to equation 2