a) 5 ( x + 2 ) = 9 ( 10 – 2x )
b) ( x + 5 ) ( x – 3 ) + x^2 – 25=0
c) x^4 – 2x^2 – 144x -1295=0
a) 5 ( x + 2 ) = 9 ( 10 – 2x ) b) ( x + 5 ) ( x – 3 ) + x^2 – 25=0 c) x^4 – 2x^2 – 144x -1295=0
By Samantha
By Samantha
a) 5 ( x + 2 ) = 9 ( 10 – 2x )
b) ( x + 5 ) ( x – 3 ) + x^2 – 25=0
c) x^4 – 2x^2 – 144x -1295=0
a. => 5x + 10 = 90 – 18x
=> 5x + 18x = 90 – 10
=> 23x = 80
=> x = 80/23
b. x^2 – 3x + 5x – 15 + x^2 – 25= 0
=> 2x^2 + 2x – 40 = 0
=> 2( x^2 + x -20) = 0
=> 2 ( x^2 – 4x + 5x -20) = 0
=> (x-4)(2x+5) = 0
=> x = 4, x = -5/2
a) 5 ( x + 2 ) = 9 ( 10 – 2x )
⇔ 5x+10=90-18x
⇔23x=80
⇔ x=80/23
b) ( x + 5 ) ( x – 3 ) + x^2 – 25=0
⇔x²+2x-15+x²-25=0
⇔ 2x²+2x-40=0
⇔x²+x-20=0
⇔(x+5)(x-4)=0
⇔x=-5
x=4