Question

Please help,

How do I solve this?

a) (x^2 -4x)*(x^2 +2x-3)=0

and

b)2x^3+7x^2-4x=0

Answer 1

for your first question, you know that either (x^2 -4x) or (x^2 +2x-3) would be equal to zero so solve each

(x^2 -4x)=0 AND (x^2 +2x-3) = 0

Answer 2

for your second question, you can factor out of x

2x^3+7x^2-4x=0
x(2x^2+7x-4)=0 divide both sides by x
(2x^2+7x-4)=0
2x^2+7x-4=0 can you solve this quadratic ?

Answer 3

Hey, @SolomonZelman ! Didn't even notice you replied!
Um, Can you show me how you solve one of the equation on a) ?
And in b), don't i use the ax^2+bx+c=0 and then use -b+/- sqrt(b-4ac)/2ac ?

Answer 4

for a)

(x^2 -4x)=0 AND (x^2 +2x-3) = 0
x^2-4x=0 x^2+2x-3=0
x(x)-4(x)=0 (x-1)(x+3)=0
(x-4)x=0
x-4=0 x-1=0 and x+3=0
x=4 x=1 x=-3





for b)

2x^3+7x^2-4x=0

x(2x^2+7x-4)=0

2x^2+7x-4=0

(2x-1)(x+4)=0

2x-1=0 and x+4=0
2x=1
x= 1/2 x= -4

Answer 5

factoring is the best !

Answer 6

@SolomonZelman Thank you, thank you, thank you!! :D

Answer 7

You welcome !