What are you trying to find?
I think its c your welcome
Answer:
20,365.7 seconds
Step-by-step explanation:
First, we need to know how to convert yards to miles, as the question is in miles. We know that 1 mile is equivalent to 1760 yards. So we have:
1 mi = 1760 yards
If we multiply both sides by 81:
81 mi = 142,560 yards
And we know that the sprinter needs 8 second to run 56 yards:
8 s = 56 yards
If we divide both sides by 56 we get the time he needs for 1 yard:
8/56 s = 56/56 yards
1/7 s = 1 yard
So, takes him 1/7 seconds to run one yard. At this rate he runs 142,560 yards in:
(1/7) * 142,560 = 20,365.7
So, he needs 20,365.7 seconds to run 81 miles (142,560 yards)
Easiest method solving 2 unknowns is Substitution.
So there will normally be 2(ormore)equations given.
Say
X+Y= a
bX=cY + d
a b c d are numbers they give
So first we rearrange the first equation
X = a - Y
No we substitute this into the 2nd equation so that we can get Y
since we know X = a-Y,
b(a-Y) = cY + d
we rearrange and we can find Y for this, it is just Y and numbers
hence finding Y, we sub the value for Y into X = a-Y and we get X also .
