1/2 = 3/6
5 gallons of water changed it to 5/6, so that would mean 2/6 would be 5 gallons worth.
5 x 3 = 15.
Hope this helps.
Step-by-step explanation:
You said the other one would be the last haha just kidding I'm glad to help.
16. 
First, get rid of that parenthesis.

Now multiply both sides by 2 so that you can isolate k


19. 
This is a pretty easy one. If you didn't know, 121/11 is actually 11 :)

Simply multiply by 3 to isolate r :)


Area of trapezoid : (Base 1 + base 2) x h x 1/2
Let's solve!
( 2+6) x 5 X1/2
= 40x1/2
=20
20 in squared is the area!
Answer:
5.1 cm
. . . . . .
All we have to do is convert our 51mm to centimeters.
We divide the length value by 10 to get our centimeters.
51 divided by 10 = 5.1
All we have to do is move our "invisible decimal"
In my way, every whole number has an invisible decimal at it's end.
For ex: '60.'
We can get into exponents. 10 is 10¹, any exponent is the number of zeros at the end of a number may have. Ex: '10² = 100'
We can move our decimal to the left since we are dividing. The amount of exponent numbers are the amount you move it, multiplying and dividing are different things with that.
Let's get back on topic.
Moving our decimal to the left with dividing is 5.1 since 10¹ has a "1" as it's exponent, making us move it "1" to the left.
Multiplying is going the right way.
I hope this helps.
15+3x-4+6x= 9x+11 add 6+3 then subtract 15-4
3y-4x+8x-y= 4x+2y add -4+8 then subtract 3-1
5x+8x+10x-3x= 20x Add 10+5+8 to get 23 then subtract 3