AM = 5x - 2 and MB = 2x + 19, Find the length of AB

The answer would be: -0.01

Step-by-step explanation:

1) State what is given

AM = 5x -2 and MB = 2x +19

2) Make an equation that can satisfy the problem

AM + BM = AB

This is the equation, because if I am to put this on a line,

A                        M                         B

---

You can see that is you combine the lengths AM and BM you can find the total length of  AB.

A                        M         +           M                        B    

--          +           --

(M point is actually one point, but I am trying to show that if the line were to be cut in half, then put back together you get you full length, which is AB)

3) Substitute

(5x - 2) + (2x + 19) = AB

4) Now Solve!

5x - 2 + 2x + 19 = AB

(Rearrange to combine like terms)

5x + 2x + 19 - 2 = AB

7x + 17 = AB

(That is your equation to find AB! But they want the specific length)

So...

We solve it!

7x = -17

(By moving the 17 to the other side of the = sign, it becomes negative)

7x = -17

7       7

(Dividing both sides by 7 in order to get x alone)

x = -2.43

(I rounded to the hundredths place)

Now substitute that into x into you original equation)

5(-2.43) - 2 + 2(-2.43) + 19 = AB

-12.15 - 2 - 4.86 + 19 = AB

-14.15 - 4.86 + 19

-19.01 + 19 = -0.01

= -0.01

(I believe this would be the answer, but it doesn't seem to fit right, so please understand, that if this is wrong, I AM SO SORRY ;-;)

(I tried my best on this problem, but I bet it isn't the answer, so if I get this wrong tell me so that I can remove it! :)

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.