Answer:
257 is prime.
Step-by-step explanation:
To evaluate if a number is prime, we just need to evaluate it for the prime numbers that are equal or lesser than the said number's square root.
In this case, √257 = 16.03 so we just need to see if 257 is divisible by <u>2, 3, 5, 7, 11 and 13</u> (the prime numbers that come before 16)
- 257 is odd, so it is not divisible by 2.
- The sum of its digits is 14, therefore, it is not divisible by 3.
- 257 ends in 7, therefore it's not divisible by 5.
- 257/ 7 = 36.71 so it's not divisible by 7.
- 257/ 11 = 23.36 so it's not divisible by 11
- Finally 257 / 13= 19.76 so it's not divisible by 13.
Therefore, 257 is prime.
Answer:
C}
Step-by-step explanation:
Answer:
True
Step-by-step explanation:
Cant really provide step by step per se.
Answer:
where is the figure?
Step-by-step explanation:
I can't see a figure
Answer:
(- 4, 27 )
Step-by-step explanation:
Equate the right sides of both equations, that is
x² - 2x + 3 = - 2x + 19 ← subtract - 2x + 19 from both sides
x² - 16 = 0 ← in standard form
(x - 4)(x + 4) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 4 = 0 ⇒ x = 4
x + 4 = 0 ⇒ x = - 4
Substitute these values into f(x) = - 2x + 19
f(4) = - 2(4) + 19 = - 8 + 19 = 11 ⇒ (4, 11 )
f(- 4) = - 2(- 4) + 19 = 8 + 19 = 27 ⇒ (- 4, 27 )
