David weighs 20lbs.more than katy ,while Jonathon weighs 120lbs. less than three times katy's weight. If David and Jonathon weigh the same amont , how mush does katy weigh? How much much does David and Jonathon weigh?
I think it is 42 I don't know
Katy' weight --- x
David ------ x+20
Jonathan --- 3x - 120
3x-120 = x+20
2x = 140
x = 70
sub back into my definitions for their weights
Tell me how you got 42 ??
To find out how much Katy weighs, let's break down the given information:
Let's assume Katy's weight as 'x' lbs.
According to the given information:
David weighs 20lbs more than Katy, so David's weight is x + 20 lbs.
Jonathon weighs 120lbs less than three times Katy's weight, so Jonathon's weight is 3x - 120 lbs.
Lastly, it is given that David and Jonathon weigh the same amount:
Therefore, we have the equation: x + 20 = 3x - 120.
To solve this equation, we can start by simplifying it:
20 + 120 = 3x - x.
140 = 2x.
Now, we can solve for x by dividing both sides of the equation by 2:
x = 140/2.
x = 70.
So, Katy weighs 70 lbs.
To find the weights of David and Jonathon, we can substitute the value of Katy's weight into their respective equations:
David's weight = x + 20 = 70 + 20 = 90 lbs.
Jonathon's weight = 3x - 120 = 3 * 70 - 120 = 150 lbs.
Therefore, David weighs 90 lbs and Jonathon weighs 150 lbs.