Answer:
You would need 23 inches to build it
You would move the decimal over until there is one number left. So the answer would be 1 • 10 to the 6th power.
Filling in 16 for <em>a</em>, we have ...
... lower limit ≤ heart rate ≤ upper limit . . . . . . . this is the meaning of upper and lower limits
... 0.5×(220 -16) ≤ heart rate ≤ 0.9×(220 -16) . . . . . substitute given expressions
... 0.5×204 ≤ heart rate ≤ 0.9×204 . . . . . . . . . . . . . begin expression evaluation
... 102 ≤ heart rate ≤ 183.6
<span>y=3x
2. x=-y
2x+y=-2
3. 2x+2y=4
x=10-3y
4. y=7-x
2x+3y=-1</span>