Question

alguém desenrola essa aí?​

Answer 1

Resposta:

Explicação passo-a-passo:

(√5+x)²=(7-√20-x)²

X+5=49-14√20-x+20-x

X+5=69-14√20-x-x

14√20-x=69-x-x-5 (÷2)

(7√20-x)²=(32-x)²

49(20-x)=1024-64x+x²

980-49x-1024+64x-x²=0

-44+15x-x²=0

X²-15x+44=0

X(x-4)-11(x-4)=0

X-4=0

X=4

X-11=0

X=11

Answer 2

(√(x+5) + √(20-x))² = 49

(x+5 + 20 - x + 2√(x+5)(20-x)) = 49

(25 + 2√(20x-x²+100-5x) ) = 49

25 + 2√(15x-x²+100) = 49

2√(15x-x²+100) = 49-25

√(15x-x²+100) = 24/2

√(15x-x²+100) = 12

(15x-x²+100) = 144

15x-x²+100-144=0

-x²+15x-44=0

x =( -15 +/- √(225-4*(-1)*(-44)))/-2

x = (-15 +/- √49)/-2

x = (-15 +/- 7)/-2

x1 = (-15 + (-7))/-2 = (-15 -7)/-2 = -22/-2=11

x2 = (-15 -(-7))/-2 = (-15+7)/-2 =-8/-2 = 4