How many solutions does the equation 2x − 2x − 7 = −7 have?

Hey there!

This equation has infinite solutions.

To solve for this equation, first add -7 to both sides in order to get rid of the constant:
2x-2x-7=-7
2x-2x=0

Now, combine your like terms or add 2x and -2x together:
2x-2x=0
0=0

Because you result in a true mathematical statement (0 is equal to itself), you have an infinite amount of solutions or all real solutions.

To check if this is true, plug in any number in place of x in the original staeltement to see if you result in a true statement:
Let's say x is 5
2(5)-2(5)-7=-7
10-10-7=-7
-7=-7

This proves that you have infinite solutions for your equation. :)