Answer:
hello : 5x² + 19x - 4 =(x+4)(5x - 1)
Step-by-step explanation:
5x² + 19x - 4
calculate Δ = b²- 4ac .... a = 5 b = 19 c = - 4
Δ = 19²- 4(5)(-4)= 361+80 = 441 = 21²
x1 = (-19 -21)/10 x2 = (-19+21)/10
x1 = -40/10= - 4 x2 = 2/10 = 1/5
note : ax²+bx +c = a(x - x1 ) ( x -x2) ........ a ≠0
5x² + 19x - 4 = 5 ( x +4)(x -1/5)
5x² + 19x - 4 =(x+4)(5x - 1)
