Solve the equation by completing the square. 0 = 4x2 − 72x A. x = 0, 18 B. x = -72, 90 C. x = -90, 72 D. x = -18, 0

A. x = 0, 18

Step-by-step explanation:

Step 1: GCF

4(x² - 18x) = 0

x² -18x = 0

Step 2: Complete the Square

x² -18x + 81 = 0 + 81

(x - 9)² = 81

Step 3: Solve

√(x - 9)² = √81

x - 9 = ±9

x = 9±9, or x = 0, 18

And we have our answers!

A. x = 0, 18

Step-by-step explanation:

0 = 4x2 − 72x

4x^2 - 72x = 0

x^2 - 18x = 0

x^2 - 18x + 81 = 81

(x - 9)^2 = 81

x - 9 = 9   or   x - 9 = -9

x = 18   or   x = 0

A. x = 0, 18

whats the

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional