Here's the question you clicked on:
anonnnn
The triangle on the left has a perimeter of 14, the triangle on the right has a perimeter of 21. What are x and y? Show your steps. I could sit here and figure it out by guessing and substituting, but I'm assuming there is a formula to this, so help?
The left triangle has a perimeter of 14, so x+y+y = 14 x+2y = 14 solve for x to get x = -2y + 14
the triangle on the right has a perimeter of 21, so 3x+(5/4)y+(5/4)y = 21 12x+5y+5y = 84 ... multiply everything by the LCD 4 to clear out the fractions 12x+10y = 84 12(-2y+14) + 10y = 84 ... plug in x = -2y + 14 Now solve for y
Do I plug that in back at the same equation where I plugged in the other, then solve for x?
yes, you plug it into x = -2y + 14 to find x
Thank you so much I've been working at this for hours!!