Question

Which of the following equations have exactly one solution? Choose all answers that apply: A.6x-15=6x+15 B.6x-6=6x+15 C.6x+15=6x+15 D.6x-6=15x+15

Answer 1

d) 6x - 6 = 15x + 15

Explanation:

Well let’s solve.

a)

6x - 15 = 6x + 15

Lets use the communicative property which is the moving of numbers.

We can start with -15, so we do +15,

6x = 6x + 30

Then we can do -6x

0 = 30

This is a false statement meaning there is no solution.

b)

6x - 6 = 6x + 15

We can start by doing +6

6x = 6x + 21

-6x

0 = 21

Again, this is a false statement meaning this has no solutions.

c)

6x + 15 = 6x + 15

So we do -15

6x = 6x

If this is the case then there is infinitely many solutions.

d)

6x - 6 = 15x + 15

So we can start by doing +5p6

6x = 15x + 21

Then we can do -15x

-9x = 21

then we can do 21 / -9 which is -2 1/3.

x = -2 1/3

So this has one solution.

Answer 2

Answer: D

Explanation:

In every other solution, x gets canceled out, so it has no impact on the equation. Thus, A, B, and C all have either infinite or no solution, because they have 6x on both sides of the equation.

Further proof:

6x-6=15x+15

Add(6)

6x=15x+21

Subtract(15x)

-9x=21

Divide(-9)

x = -2 3/9

Hope it helps <3