The answer is 15 because you subtract 42 and 27
(2b^4)^(-1)=1/(2b^4)
^(-1) basically means reciprocal
<span>Length = l</span>
<span>
Width = w</span>
<span>
Perimeter = p = 100
</span>
<span>Perimeter of rectangle = 2(l+w)</span>
<span>
100 = 2 (4w + w)</span>
<span>
100 = 2(5w)</span>
<span>
100 = 10w</span>
<span>
100/10 = w</span>
<span>
10 = w</span>
<span>
w = 10
Area of rectangle = length * width</span>
<span>
a = l*w</span>
<span>
a = 4w*w</span>
<span>
a = 4w^2............(1)</span>
<span>
Put the value of w in (1)</span>
<span>
a = 4(10)^2</span>
<span>
a= 4(100)</span>
<span>
a = 400 yd^2</span>
Bicycle has 2 wheels and 2 pedals
tricycle has 3 wheels and 2 pedals
EQ 1 : 2b + 2t = 170 pedals
EQ 2: 2b +3t = 206 wheels
subtract EQ 1 from EQ 2
2b +3t = 206 - 2b + 2t = 170 = t=36
there were 36 tricycles
36 x 2 = 72 pedals
170 pedals - 72 = 98 pedals left
98/2 = 49 bicycles
36 Tricycles and 49 bicycles