Question

Solve. 5x2 – 20 = 0

x = 5 and x = 4

x = 4 and x = 2

x = –5 and x = 20

x = 2 and x = –2

Answer 1

Step 1: Add 20 on both sides

Answer 2

Step 2: divide both sides by 5

Answer 3

Can you try that?

Answer 4

Sorry, did i make any mistake? :S

Answer 5

If you factored out 5 first then you will get:

\[5(x^2 - 4) = 0 \implies 5(x^2 - 2^2) = 0\]

Answer 6

IM CONFUSED

Answer 7

\(5x^2-20=0 \)
\(x^2 = 4 \)

When you take square root on both sides you'll get two solutions, right?

Answer 8

yes but sometimes it will not be applicable..

Like:

\[x^2 = 4x\]

you can't cancel x here..

Answer 9

You are right diya sorry my misunderstanding...

Answer 10

Its Okay, No Problem :)

Answer 11

@harrisonshields just do the same what diya told you to do..

Answer 12

ok so if x^2 = 4

Answer 13

@harrisonshields
\(5x^2-20=0 \)

Add 20 on both sides
\(5x^2 - 20 +20 = 20 \)
\(5x^2=20\)

Divide both sides by 5
\(5x^2/5 = 20/5 \)
\(x^2 = 4 \)

Answer 14

i get 2 and 4/2?

Answer 15

Don't you think they both are same @harrisonshields

Answer 16

oh so - and + 2

Answer 17

\[\sqrt{x^2}=\sqrt{4}\]\[x= \pm 2\]

Answer 18

Are you hungry??

Then why you ate 2?? @harrisonshields
ha ha ha.

Answer 19

Right! @harrisonshields

\(\pm 2 \) because \( 2^2 = (-2)^2 = 4\)