3 years ago

Solve by Substitution: 3x - y = 4 y = 6 - 2x

1 answer:

4 0

Substitute 6 - 2x for y in the first equation

3x - (6 - 2x) = 4

5x - 6 = 4

5x = 10

x = 2

Plug 5 for x in either equations (I'll use the second equation)

y = 6 - 2 * 2

y = 6 - 4

y = 2

(2,2) is the solution.

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-1/2=y-1 <br> I don’t understand this

Greeley [361]

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3 years ago

How many five-card hands (drawn from a standard deck) contain exactly three fives? (A five-card hand is any set of five differen

VashaNatasha [74]

Answer:

4512.

Step-by-step explanation:

We are asked to find the number of five-card hands (drawn from a standard deck) that contain exactly three fives.

The number of ways, in which 3 fives can be picked out of 4 available fives would be 4C3. The number of ways in which 2 non-five cards can be picked out of the 48 available non-five cards would be 48C2.

$4C3=\frac{4!}{3!(4-3)!}=\frac{4*3!}{3!*1}=4$