Question 311320
Mark weighs 74 pounds. Together, he and his sister weighs six pounds more than three times the weight of his sister. What is the weight,of marks sister.
Okay, lets get started. First, we need to set up an equation. Let's call his sister's weight "x" for now.
74+x=3x+6
Now, let us subtract 6 from both sides.
74-6+x=3x+6-6 which equals
68+x=3x
Now, lets subtract an x from both sides
68+x-x=3x-x which equals
68=2x
Finally, we should divide both sides by 2 to get rid of the 2 in front of the x.
68/2=2x/2
x=34, so his sister's weight is 34 pounds.
I hope I helped!