5(-3.4k - 7) + (3k + 21) = -17k - 35 + 3k + 21 = -14k - 14
Since the quadratic formula of ax^2+bx+c is
x=(-b+-(plus OR minus) sqrt (b^2-4ac))/2a, we can get that a is 1 (since 1*x^2 is x^2), b is 4, and c is -16, so x=(-4+-sqrt((-4)^2-4*1*(-16)))/2*1
= (-4+-sqrt(16-(-64)))/2=(-4+-sqrt(80))/2 which is either (-4+sqrt(80))/2 or
(-4-sqrt(80))/2. Since 80 is divisible by 4 (aka 2 squared), we can write sqrt(80) as 2*sqrt(20) as 4 goes into 80 20 times, getting (-4+2sqrt(20))/2 or
(4-2sqrt(20))/2, and crossing out the 2's we get (-2+sqrt(20)) or (-2-sqrt(20))
Can you please take the pictures again I would love to help you! <3
Answer:
b
Step-by-step explanation:
180 minus 82
Answer:
Option C, (x2 − 3)(x2 + 3)(x4 + 9)
Step-by-step explanation:
x^8 - 81 factors as (x^4 - 9)(x^4 + 9)
(x^4 - 9)(x^4 + 9) factors as (x^2 - 3)(x^2 + 3)(x^4 + 9)
Answer: Option C, (x2 − 3)(x2 + 3)(x4 + 9)