Question

3. Tell which number is prime: 18, 42, 68, 79.

Answer 1

Answer:

1) 79

2) 400

3) 29

Step-by-step explanation:

1) To find : Tell which number is prime: 18, 42, 68, 79.

Solution :

A prime number is defined as number which is only divisible by 1 and itself.

As 18,42 and 68 were divisible by 2.

But 79 is not divisible by any number.

Which means 79 is the only prime number which is divisible by 1 and itself.

2) To find : The value of the expression $48\times 8+4\times 4$

Solution :

The expression,

$48\times 8+4\times 4$

$=384+16$

$=400$

Therefore, $48\times 8+4\times 4=400$

3) Evaluate : $(c- b)^2 + a^2$ for a=-5, b=-2 and c=-4

Solution :

The expression is $(c- b)^2 + a^2$

Substitute the values, a=-5, b=-2 and c=-4

$(c- b)^2 + a^2=(-4-(-2))^2+(-5)^2$

$(c- b)^2 + a^2=(-4+2)^2+25$

$(c- b)^2 + a^2=(-2)^2+25$

$(c- b)^2 + a^2=4+25$

$(c- b)^2 + a^2=29$

Answer 2

3. All of those numbers are prime. A prime number is a whole number greater than 1 whose only factors are 1 and itself. A factor is a whole numbers that can be divided evenly into another number.

4. 97

4. 14