Is Mabel correct? A. Mabel is correct.
B. No, she made a mistake in step 2
C. No, she made a mistake in step 3
D. No, she made a mistake in step 4

Let's solve your equation step-by-step.
(
4
x
−
3
)
(
(
x
−
2
)
2
)
=
4
x
3
−
19
x
2
+
4
x
−
12
4
x
3
−
19
x
2
+
28
x
−
12
=
4
x
3
−
19
x
2
+
4
x
−
12
Step 1: Subtract 4x^3 from both sides.
4
x
3
−
19
x
2
+
28
x
−
12
−
4
x
3
=
4
x
3
−
19
x
2
+
4
x
−
12
−
4
x
3
−
19
x
2
+
28
x
−
12
=
−
19
x
2
+
4
x

12
Step 2: Add 19x^2 to both sides.
−
19
x
2
+
28
x
−
12
+
19
x
2
=
−
19
x
2
+
4
x
−
12
+
19
x
2
28
x
−
12
=
4
x
−
12
Step 3: Subtract 4x from both sides.
28
x
−
12
−
4
x
=
4
x
−
12
−
4
x
24
x
−
12
=
−
12
Step 4: Add 12 to both sides.
24
x
−
12
+
12
=
−
12
+
12
24
x
=
0
Step 5: Divide both sides by 24.
24
x
24
=
0
24
x
=
0

x
=
0

Def is a scalene triangle