Question

What are the solutions of 3x2 = 21x?
A. x = 3, x = 7
B. x = 3, x = −7
C. x = 0, x = 7
D. x = 0, x = −7

Answer 1

C

Answer 2

3x2 = 21x
3x2-21x=0
3x(x-7)=0

so x=0 or x=7

Answer 3

C. x = 0, x = 7

x^2 = 7x
x^2-7x=0
x(x-7) = 0
Zero Product Property
x = 0 or x = 7

Answer 4

c