Use the elimination method to solve the system of equations. choose the correct ordered pair. 4x4y-27 5x-y-18
a. (6,9)
b. (2,8)
c. (3,6)
d. (5,7)

(5,7)

Step-by-step explanation:

4x+y=27

5x-y=18

Since we want to solve this by elimination we need the lines to be in the same form, and a column with opposite variables or same variables. We actually have both of these.

Both equations are in the form ax+by=c.

The column that contains the y's, we have opposites there. That is the opposite of y is -y.  When you add opposites, you get 0.

So we just add vertically now.

4x+y=27

5x-y=18

Add

9x+0=45

9x    =45

Divide both sides by 9:

x      =45/9

Simplify:

x       =5

Now to find y, you just need to use one of your equations (just pick one) along with x=5.

I guess I will choose 4x+y=27 with x=5.

4x+y=26 with x=5

4(5)+y=27

20+y=27

Subtract 20 on both sides:

y=27-20

y=7

So the solution (x,y) is (5,7).

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m