Question

Which value, when placed in the box, would result in a system of equations with infinitely many solutions?

y = 2x – 5

2y – 4x =

Answer 1

the missing number is -10.

Explanation:

2x+b/2=2x-5

b/2=-5

b=-10

- jess ♡

Answer 2

For a system of equations to have infinitely many solutions, they have to intersect infinite times. For linear functions, this can only happen if they are the same line. Let's rearrange the second equation so that it is easier to compare the two functions.

2y-4x=b
2y=4x+b
y=2x+b/2

Because the linear functions must be the same function, set them equal to each other to find b.

2x+b/2=2x-5
b/2=-5
b=-10

So the missing number is -10.