-10............................
Answer:
3800
Step-by-step explanation:
Variables:
O - Original cost
N - New cost
c - change factor
Step 1:
Recognize that if something decreases by 19%, it is worth 19% <em>less</em>
This means that the new price, fractionally, is 100% - 19% = 81%
So we can use c as 0.81 (81/100)
Step 2:
Write an equation to represent what is happening
N = O * c
Step 3:
Sub in what we know
3078 = O * 0.81
Step 4:
Rearange and solve
O = 3078 / 0.81 = 3800
It would be 1............
X² - 8x = -10
to have a complete square, we must have this format:
a² + 2ab + b²
a² = x²
2ab = -8x ⇒ 2(x)(-4)
b² = -4² = 16
x² - 8x + 16 = -10 + 16
x² - 8x + 16 = +6
(x-4)² - 6 = 0
Both sides must have an additional value of 16.
Answer:
Step 2
Step-by-step explanation:
In step 2 the expression was 40+20 which would have been 60 but he might have thought addition sign was subtraction so he did 40-20 which is 20 so he is wrong made mistake in step 2