Question

qual a resposta de (5x-2).(2x-1)?​

Answer 1

Resposta:

$10x^2-9x+2$

Explicação passo-a-passo:

$\left(5x-2\right)\left(2x-1\right)\\\\=5x\cdot \:2x+5x\left(-1\right)+\left(-2\right)\cdot \:2x+\left(-2\right)\left(-1\right)\\\\=5\cdot \:2xx-5\cdot \:1\cdot \:x-2\cdot \:2x+2\cdot \:1\\\\=10x^2-9x+2$

Answer 2

(5x-2)(2x-1)

10x²-5x-4x+2

10x²-9x+2=0

∆ =(-9)²—4*10*2

∆ = 81-80

∆ = 1

x1=(9+1)/2*10

x1=10/20=1/2

x2 =(9-1)/2*10

X2 =8/20

x2 = 2/5