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
11a:
3x+5=5x-57
3x-5x=-57-5
-2x=-62
x=31
11b:
2x+2x+4x+150+4x+150=360
12x+300=360
12x=360-300
12x=60
x=5
hope this helped !!
Sum of all adjacent angles is 180°.
3x + 12 + x = 180
4x + 12 = 180
4x = 168
x = 42°
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Answer: x = 42°
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ANSWER
Average Rate of Change

EXPLANATION
To find the average rate of change of y=f(x) from x=a to x=b means finding the slope of the secant line joining the points
(a,f(a)) and (b,f(b))
The slope of the secant line joining these points is

This gives the average rate of change of the function.
You have to simplify like this
(-5)(-8)=40