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 [tex]48\times 8+4\times 4[/tex]
Solution :
The expression,
[tex]48\times 8+4\times 4[/tex]
[tex]=384+16[/tex]
[tex]=400[/tex]
Therefore, [tex]48\times 8+4\times 4=400[/tex]
3) Evaluate : [tex](c- b)^2 + a^2[/tex] for a=-5, b=-2 and c=-4
Solution :
The expression is [tex](c- b)^2 + a^2[/tex]
Substitute the values, a=-5, b=-2 and c=-4
[tex](c- b)^2 + a^2=(-4-(-2))^2+(-5)^2[/tex]
[tex](c- b)^2 + a^2=(-4+2)^2+25[/tex]
[tex](c- b)^2 + a^2=(-2)^2+25[/tex]
[tex](c- b)^2 + a^2=4+25[/tex]
[tex](c- b)^2 + a^2=29[/tex]
