Diketahui a dan b merupakan akar akar persamaan kuadrat berikut.

(Persamaan 1)

4x²+21x+5=0

(4x+1)(x+5)=0

x= -1/4 =a

x= -5 =b

4(-1/4)+15=14

(Persamaan 2)

6x²-11x+3=0

(3x-1)(2x-3)=0

x=1/3 =b

x=3/2 =a

4a-3b= 3×2-3×(1/3)=6-1= 5

A. 4x^ + 21x + 5 = 0
( 4x + 1 ) ( x + 5 ) = 0
x, = -1/4 ====> a = -1/4
x,, = -5 ====> b = -5
4a – 3b = 4(-1/4) – 3(-5)
= -1 + 15 = 14

b. 6x^ – 11x + 3 = 0
( 2x – 3 ) ( 3x – 1 ) = 0
x, = 3/2 ===> a
x,, = 1/3 ===> b

4a – 3b = 4(3/2) – 3(1/3)
= 6 – 1 = 5

Semoga bisa membantu ya