You're going to use the substitution method for this.
First, we know that Y = x-7, so we can plug x-7 into everywhere we see Y!
3x - 3(x - 7) = 21
then we simplify
3x - 3x + 21 = 21
^ ^
These cancel out!
So we're left with...
21 = 21
That means that the solution to this equation is all real numbers!
You would add 13+19=32
then add 32+7 which equals 39 :P
Answer:
It would take them 6.667 minutes to paint 50 square feet together.
Step-by-step explanation:
This is a classic work problem. If Sam can do the job in 10 minutes, she can get done 1/10 of the job in one minute. If you can do the job in 5 minutes, you can 1/5 of the job done in one minute. To find out how many minutes it will take them together to paint 25 square feet, set the addition of their times equal to 1/x:

x is how long it takes them to get the job done together. Find the common denominator and multiply it through be everything to get rid of the denominators altogether. That denominator is 10x:

Simplify to get the simple equation x + 2x = 10 and 3x = 10. That means that x=3 1/3. That's how long it takes to do 25 square feet. Double that time for 50 square feet.
Answer:
ok so the
the length is 20
the width is 10
the height is 5
Step-by-step explanation:
ok i got this by guess and check
twice as long as it is wide so i am saying that it is 10 wide so it would be 20 long and if it is twice as wide as it is tall then it is 5 because 10/2=5
20+10+5=35
Answer:
The 20% markdown makes it $140. That means you have saved $35.
Explanation:
I hope this helps :)