Question

y²-25=0 
5x²-10x=0
5+x²=9
2x²-7x=0 
ME AJUDEM ... VALEU !!!!

Answer 1

y² - 25 = 0
y² = 25
y = +ou- $\sqrt{25}$
y = +ou- 5

5x² - 10x = 0
5x(x-2) = 0
5x = 0
x = 0
x - 2 = 0
x = 2

5 + x² = 9
x² = 9 - 5
x² = 4
x = +ou- $\sqrt{4}$
x = +ou- 2

2x² - 7x = 0
x( 2x - 7) = 0
x = 0
2x - 7 = 0
2x = 7
x = $\frac{7}{2}$

Espero ter ajudado :)

Answer 2

y²-25=0 
a=1
b=0
c=-25

Delta=0²-4*1*-25
Delta=0+100
Delta=100


x'=-0+V100/2*1
x'=-0+10/2
x'=10/2
x'=5

x''=-0-10/2
x''=-10/2
x''=-5









5x²-10x=0
a=5
b=-10
c=0

Delta=-10²-4*5*0
Delta=100-0
Delta=100

x'=-(-10)+V100/2*5
x'=10+10/10
x'=20/10
x'=2

x''=-(-10)-V100/2*5
x''=10-10/10
x''=0/10
x''=0







5+x²=9
x²+5-9=0
x²-4=0
a=1
b=0
c=-4

Delta=0²-4*1*-4
Delta=0+16
Delta=16

x'=-0+V16/2*1
x'=-0+4/2
x'=4/2
x'=2

x''=-0-V16/2*1
x''=-0-4/2
x''=-4/2
x''=-2









2x²-7x=0 
a=2
b=-7
c=0

Delta=-7²-4*2*0
Delta=49-0
Delta=49

x'=-(-7)+V49/2*2
x'=7+7/4
x'=14/4 (simplifica por 2)
x'=7/2

x''=-(-7)-V49/2*2
x''=7-7/4
x''=0/4
x''=0