10 + 2p
increases by means addition
product means multiplication
2 Letters chosen among 6 with no repeat:
a) the first has 6 ways
the second has 5 ways
Then to choose 2 letters among 6, with no repeat, there are 6x5 = 30 ways
b) 3 numbers are taken from the digits 0 through 9 with repeats (total = 10)
the first has 10 ways
the second has 10 ways
the third has 10 ways
Then to choose 3 numbers among 10, with repeat, there are 10x10x10= 1000 ways
And the total serial numbers that can be generated is
30 x 1000 = 3000
Answer:
There are 24 nickels
Step-by-step explanation:
Let x represent the number of nickels
Let y represent the number of quarters
—————————————————————
Value Value
Type Number of of
of of each all
Coin Coin Coin Coin
—————————————————————
Nickels | x | $0.05 | $0.05x
Quarters | y | $0.25 | $0.25y
—————————————————————
Totals 28 ——— $2.20
•••••••••••••••••••••••••••••••••••••••••••••••••
The first equation comes from the “Number of coins” column.
(Number of nickels) + (Number of quarters) = (total number of coins)
Equation: x + y = 28
—————————————————————
The second equation comes from the “value of all coins” column.
(Value of all nickels) + (Value of all quarters) = (Total value of all coins)
0.05x + 0.25y = 2.20
Remove the decimals by multiplying each term by 100:
5x + 25y = 220
—————————————————————
So we have the system of equations:
{x + y = 28
{5x + 25y = 202
Solve by substitution. Solve the first equation for y:
x + y = 28
y = 28 - x
Substitute (28 - x) for y in 5x + 25y = 220
5x + 25 (28 - x) = 220
5x + 700 - 25x = 220
-20x + 700 = 220
-20x = -480
x = 24
The number of nickels is 24.
————————————————————
Substitute in y = 28 - x
y = 28 - (24)
y = 4
The number of quarters is 4.
————————————————————
Checking:
24 nickels is $1.20 and 4 quarters is $1.00
That’s 28 coins.
Indeed $1.20 + $1.00 = $2.20
————————————————————
Answer:
x = -5
y = -2
Step-by-step explanation:
<em><u>Since you have y, plug that into the equation:</u></em>
-2x - 7y = 24
-2x - 7(-2) = 24
-2x + 14 = 24
<u><em>Then, subtract 14 from both sides:</em></u>
-2x + 14 = 24
- 14 - 14
__________
-2x = 10
<u><em>Finally, divide both sides by -2:</em></u>
-2x = 10
x = -5
So now you have, x = -5 and y = -2.
A rectangle is a four sided figure with four right angles but it does not have congruent sides because two of its sides are longer than the other two.