Move constant to other side
add 1
4c^2-8c=1
divide by 4 to make leading coeficient 1
c^2-2c=1/4
take 1/2 of linear coeficient and square it
-2/2=-1, (-1)^2=1
add that to both sides
c^2-2c+1=1/4+1
factor perfect squaer and add
(c-1)^2=5/4
square root both sides
c-1=+/-(√5)/2
add 1
c=1+/-(√5)/2
c=2.12 or -0.12
<span>Twice the sum of a number and 3 = 2(n + 3)
</span><span>three times the difference of the number and 3 = 3(n - 3)
so
</span><span>Twice the sum of a number and 3 is equal to three times the difference of the number and 3:
</span>2(n + 3) = 3(n - 3)
2n + 6 = 3n - 9
n = 15
answer
2(n + 3) = 3(n - 3)
n = 15
First change 0.8 to a fraction which is 4/5. Then find a common denominator between 5/8, 4/5, and 3/5. The common denominator is 40. So then you multiply the numerator by the same number you multiply the denominator by. I'll do 5/8 as an example; to get 40 as your denominator multiply 8 by 5, and then multiply 5 by 5. The fraction you'll get is 25/40. The rest of the fractions are 4/5 - 32/40 and 3/5 - 24/40. Then order them either from smallest to largest (24/40, 25/40, 32/40) or largest to smallest (32/40, 25/40, 24/40).
