Answer:
(B)
4 +/- 3 sqrt(2) or 4+3sqrt(2) and 4-3sqrt(2)
Step-by-step explanation:
4(c-4)^2=72
4(c-4)(c-4)=72
foil the parenthesis (first, outside, inside, last)
4(c^2 -4c -4c +16)=72
4(c^2-8c+16)=72
divide each side by 4
c^2-8c+16=18
subtract 18 from both sides
c^2-8c-2
use quadratic formula
((-b +/- sqrt((-b^2)-4ac)))/2a
((-(-8)+/-sqrt((-8)^2-4(1)(-2)))/2(1))
(8+/-sqrt(64-(-8)))/2
(8+/-sqrt(64+8))/2
(8+/-sqrt(72))/2
(8+/-sqrt(36 * 2))/2
(8+/-6sqrt(2))/2
4+/-3sqrt(2)
or 4+3sqrt(2) and 4-3sqrt(2)
Answer: a
Step-by-step explanation: its getting rid of water and the original is 40
Distributive Property: a ( b + c) = (a*b) + (a*c)
b) x(x + 9) = x*x + 9*x
= x² + 9x
c) x² - 18x
x² = x * x
18x = 18 *x
G C F = x
Greatest common factor in both the terms is 'x'.Take the common variable from both the terms.
x² - 18x = x*x - 18*x
= x (x - 18)
Standard form. Factored form
x² x*x
x² + 9x x(x +9)
x² - 18x x(x - 18)
-x² + 10x x(-x + 10) = x(10 -x)
-x² - 2.75x -x(x + 2.75)
We can get two different equations from this:
3x = 18
and
3x = -18
So:
x = 6, x = -6
x = {6, -6}