jan, mya, and Sara ran a total of 64 miles last week. jan and mya ran the same number of miles. Sara ran 8 less miles than mya. how many miles did Sara run?

Sagot :

So,

We'll just use A to represent both Jan and Mya's miles, since they ran the same number.

We have the equations:
1. Jan (J) = Mya (M)
2. Sara (S) = M - 8
3. 2A + S = 64
J = M
S = M - 8

We'll just use A to represent both J and M.

S = M - 8

We'll use Elimination by Substitution.
2A + A - 8 = 64

Collect Like Terms
3A - 8 = 64

Add 8 to both sides
3A = 72

Divide both sides by 3
A = 24

Since
A = J
and
A = M
and
J = M
then
J = 24
M = 24

Substitute
S = 24 - 8
S = 16

Check
24 + 24 + 16 = 64
64 = 64 This checks.

So,
J = 24
M = 24
S = 16
Jan=X mya=X Sara=X-8 3X-8=64 3X=72 X=24 milesof Jan and mya 24-8=16 miles for Sara