Question

How do you do this ?
Solve the equation: 4x2 = 36
A. {6, -6}
B. {3, -3}
C. {2/3, -2/3}
D. {3/2, -3/2}

Answer 1

4x2 = 36
4x2 -36 =0
Factorise it, put each factor =0, and solve it, try ~

Answer 2

B

Answer 3

so 6,-6 ?

Answer 4

you also can take out the common factor first... i meant the '4'

Answer 5

nope..

Answer 6

factorise 4x2 -36 first

Answer 7

so i need to find the GCF of 36 ?

Answer 8

36 and 4x^2

Answer 9

4 .

Answer 10

is the GCF

Answer 11

yes.. so you can rewrite it into 4(x^2-9), so now, factorise (x^2 -9)

Answer 12

2/3 ?

Answer 13

nope...

Answer 14

factorise (x^2 -9)

Answer 15

thats what i got. its either that or 3/2

Answer 16

\[x^2 -9 = (x-3)(x+3)\]

Answer 17

so So if i do the square root of nine and times the answer two times that will give me my answer ?

Answer 18

4x2 -36 =0
4(x^2 -9) =0
4(x+3)(x-3) =0
(x+3)(x-3) =0
x+3 =0 or x-3 =0
x=-3 or x=3

Answer 19

no, \[\sqrt{9} \times 2 = 3\times2 = 6\]

Answer 20

ok

Answer 21

do you understand?

Answer 22

yes