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2 years ago

Find a counterexample for the statement. If p is prime, then p2 + 4 is prime.

Mathematics

1 answer:

uysha [10]2 years ago

7 0

P=2 then 2^2+4=8
P=11 then 11^2+4=125

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Find the area of a circle with a circumference of 30 pie meters

vesna_86 [32]

Step-by-step explanation:

Cir=30π=2πr , thus r=15 , Area=π(r^2)=225 pie meters

3 0

2 years ago

Expand and simplify this equation plz, 4(3x+5) - 5(8x+2)

omeli [17]

$4(3x + 5) - 5(8x + 2) \\ 12x + 20 - 40x - 10 \\ 12 x - 40x + 20 - 10 \\ - 28x + 10$

7 0

1 year ago

Calculate the amount and the compound interest on Rs 12.000 in 2 years at 10%

mel-nik [20]

Answer:

Amount = p( 1+r/100) ^n

= 12000 ( 1+10/100) ²

= 12000( 10/10+1/10) ²

= 12000( 11/10) ²

= 12000 x 11/10 x 11/10

= 14520 rs.

Compund interest = amount - principal

= 14520 - 12000

= 2520rs.

Next question :- no of men can complete a piece of work in 7 days = 36

No of men can complete a piece of work in 42 day = ( 36 x 7 ) ÷ 42

= 252 ÷ 42

= 6 men

5 0

2 years ago

Marco is 8 years younger than his brother Paolo. If their product of their ages is 105, how old is Marco? plz help

Nina [5.8K]

Answer:

Marco's age is 7 years old

Step-by-step explanation:

Let

x ----> Marco's age

y ----> Paolo's age

we know that

$x=y-8$ ----> $y=x+8$ ----> equation A

$xy=105$ ----> equation B

substitute equation A in equation B

$x(x+8)=105$

$x^2+8x-105=0$

Solve the quadratic equation

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$x^2+8x-105=0$

$a=1\\b=8\\c=-105$

substitute in the formula

$x=\frac{-8(+/-)\sqrt{8^{2}-4(1)(-105)}} {2(1)}$

$x=\frac{-8(+/-)\sqrt{484}} {2}$

$x=\frac{-8(+/-)22} {2}$

$x=\frac{-8(+)22} {2}=7$

$x=\frac{-8(-)22} {2}=-15$

Remember that the solution cannot be a negative number

The solution is x=7

therefore

Marco's age is 7 years old

4 0

3 years ago

If Carbon 12 is named 12 because it has 6 protons

tester [92]

Answer:

Step-by-step explanation:

8 0

2 years ago