Question

Selesaikan dngan cra persamaan linear dan persamaan kuadrat
a.4xkuadrat-4x+1=0
b.2xkuadrat+7x-4=0

Answer 1

A.
4x^2 -4x +1=0 --> a = 4 b= -4 c=1
pakai rumus abc
(-b±√(b^2 - 4ac))/2a
(4±√(-4^2 - 4.4.1))/2.4 = (4±√(16 - 16))/2.4
= (4±√(0))/8
=4±0/8
x1= 4+0/8=4/8=1/2
x2= 4-0/8 = 4/8 = 1/2
x1=x2
b.
2x^2 + 7x -4 =0
a = 2 b=7 c=-4
(-b±√(b^2 - 4ac))/2a
(-7±√(7^2 - 4.2.-4))/2.2
(-7±√(49+32))/4
(-7±√(81))/4 = -7±9/4
x1= -7+9/4 = 2/4 = 1/2
x2= -7-9/4 = -16/4 = -4