The height is 10yd. 60 is the are of the triangle and the formula for finding the area is b*h1/2=area so you have to multiply 60 by 2 then dived the answer you get by 12 to find out the length. Hope this helps!
-2x + 7 and 0.5x - 5 are both equal to y, so they must be equal to each other.
-2x + 7 = 0.5x - 5
2.5x = 12
x = 4.8
X = x4
And
Y = x2
Because of the fact the cows have 4 legs and chickens have 2