Question

me ajudaaaaaa!!!!!!!!!!!​

Answer 1

Explicação passo-a-passo:

(x-4).(x-5) = 0

x²-5x -4x+20 = 0

x² -9x +20 = 0

Δ = b²-4.a.c

Δ = (-9²)-4.1.20

Δ = 81-80

Δ = 1

x = -b +- √Δ /2.a

x = -(-9) +- √1 / 2.1

x = 9 +- 1 / 2

x' = 9 + 1 / 2

x' = 10 / 2

x' = 5

x" = 9 - 1 / 2

x" = 8 / 2

x" = 4

ESPERO TER AJUDADO ♡

Answer 2

Resposta:

$(x-4)(x+5)=0\\ \\x^{2}+5x-4x-20=0\\ \\x^{2}+x-20=0\\ \\delta=b^{2}-4.a.c\\ \\delta=1-4.1.(-20)\\ \\delta=1+80\\ \\delta=81\\ \\x=\frac{-b+-\sqrt{delta}}{2.a}\\ \\x=\frac{-1+-\sqrt{81}}{2}\\ \\x'=\frac{-1+9}{2}=4\\ \\x''=\frac{-1-9}{2}=-5\\ \\S~~~~\left \{ {{4;~~-5} \}} \right.$