I'm confused about the way the step by step is explained by khan academy so can someone please break this down for me? The answer is b=54.

Step-by-step explanation:

Given

w(x) = ax²+ bx +c

a=3

Soln.

w(3) = w(15) = 0

w(x) = ax² + bx + c

w(3) = a(3)² + b(3) + c ( Replace x by 3)

= 9a + 3b +c

a=3( given)

w(3) = 9(3) + 3b + c

= 27 +3b + c =0. (1)

w(15) = a(15)² + b(15) + c ( Replacing x by 15)

= 225a + 15b + c

a= 3(given)

w(15) = 225(3)+ 15b + c

= 675 + 15b + c = 0. (2)

Now solve the 2 equations by subtracting

15b + c + 675 = 0

(-) 3b + c + 27 = 0

12b + 648 = 0

12b = -648

b= -648/12 = -54

Now absolute value of b = |b| = |-54| = 54.

Hope this answer helps you

37/3

step-by-step explanation:

step 1: simplify both sides of the equation.

7x+8(x+

1

4

)=3(6x−9)−8

7x+(8)(x)+(8)(

1

4

)=(3)(6x)+(3)(−9)+−8(distribute)

7x+8x+2=18x+−27+−8

(7x+8x)+(2)=(18x)+(−27+−8)(combine like terms)

15x+2=18x+−35

15x+2=18x−35

tep 2: subtract 18x from both sides.

15x+2−18x=18x−35−18x

−3x+2=−35

step 3: subtract 2 from both sides.

−3x+2−2=−35−2

−3x=−37

step 4: divide both sides by -3.

−3x

−3

=

−37

−3

x=

37

3

definitely a. the others have almost all data points on one side of the line.

step-by-step explanation: