solve (6-2x) × (6-2x) = 20
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Hi ,
( 6 - 2x ) ( 6 - 2x ) = 20
( 6 - 2x )² = 20
6² - 2 × 6 × 2x + ( 2x )² = 20
36 - 24x + 4x² = 20
Divide each term with 4 , we get
9 - 6x + x² = 5
x² - 6x + 9 - 5 =0
x² - 6x + 4 = 0
Compare with ax² + bx + c = 0 we get
a = 1 , b = -6 , c = 4
D = b² - 4ac = ( -6 )² - 4 × 1 × 4
= 36 - 16
D = 20
x = ( -b ± √D ) / 2a
= [ -(-6 ) ± √20 ] / ( 2 × 1 )
= ( 6 ± 2√5 ) /2
= 3 ± √5
I hope this helps you.
:)
( 6 - 2x ) ( 6 - 2x ) = 20
( 6 - 2x )² = 20
6² - 2 × 6 × 2x + ( 2x )² = 20
36 - 24x + 4x² = 20
Divide each term with 4 , we get
9 - 6x + x² = 5
x² - 6x + 9 - 5 =0
x² - 6x + 4 = 0
Compare with ax² + bx + c = 0 we get
a = 1 , b = -6 , c = 4
D = b² - 4ac = ( -6 )² - 4 × 1 × 4
= 36 - 16
D = 20
x = ( -b ± √D ) / 2a
= [ -(-6 ) ± √20 ] / ( 2 × 1 )
= ( 6 ± 2√5 ) /2
= 3 ± √5
I hope this helps you.
:)
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