Answer:
A is 64 and b is 34
Step-by-step explanation:
While it's pretty obvious to most of us that
-13x=90-2y
-6x=48-2y
is a system of linear equations, it'd be well to include that info plus the instructions "solve this system of linear equations."
Subtract the 2nd equation from the first:
-13x=90-2y
+6x=-48+2y
-----------------------
-7x = 42. Then x = -42/7, or x = 6.
Now subst. 6 for x in either one of the given equations. Suppose we use the 2nd equation:
-6x=48-2y
Then -6(6)=48-2y, or -36 = 48 - 2y, or 2y = 48+ 36 = 84. Then y = 42.
The solution is (6, 42).
Let's evaluate ~
The given expression is :
plug the value of x as 3
Therefore, the required value is 20
First, I'd like to say that this question is flawed because the diameter of the spool changes as you pull the line out. Some would argue it's negligible I suppose.
At any rate, assuming there's a magic spool where the diameter doesn't change, let's find the cicumference so we can find the length of one wrap around the spool.
circumference = 2*pi*r = 2 * pi * 4cm = about 25.133 cm
Now if it turns 16 times we'll have 16 times the circumference.
16 * (25.133 cm)
= 402.128 cm
Andy would have to make 3 trips in order to cycle 21 kilometers.
