Answer:
we have (a,b,c)=(4,-2,0) and R=4 (radius)
Step-by-step explanation:
since
x²+y²+z²−8x+4y=−4
we have to complete the squares to finish with a equation of the form
(x-a)²+(y-b)²+(z-c)²=R²
that is the equation of a sphere of radius R and centre in (a,b,c)
thus
x²+y²+z²−8x+4y=−4
x²+y²+z²−8x+4y +4 = 0
x²+y²+z²−8x+4y +4 +16-16 =0
(x²−8x + 16) + (y² + 4y + 4 ) + (z²) -16 = 0
(x-4)² + (y+2)² + z² = 16
(x-4)² + (y-(-2))² + (z-0)² = 4²
thus we have a=4 , b= -2 , c= 0 and R=4
Answer:
these are supplementary
and x = 50
Step-by-step explanation:
one straight line = 180 degrees
there are only two angles making up this 180 degree line, so by definition they are supplementary
76 + 2x + 4 = 180
80 + 2x = 180
2x = 100
x = 50
Answer: 5 km walking and 30 km by bus
Step-by-step explanation:
Yochanan walked from home to the bus stop at an average speed of 5 km / h. He immediately got on his school bus and traveled at an average speed of 60 km / h until he got to school. The total distance from his home to school is 35 km, and the entire trip took 1.5 hours. How many km did Yochanan cover by walking and how many did he cover by travelling on the bus?
walking - 5km/h bus - 60km/h
distance walking - d₁ distance bus - d₂
time walking - t₁ time bus - t₂
d₁ + d₂ = 35
t₁ + t₂ = 1.5
v = d/t
vwalking = d₁/t₁
5 = d₁/t₁ ⇒ d₁ = 5t₁
vbus = d₂/t₂
60 = d₂/t₂ ⇒ d₂ = 60t₂
d₁ + d₂ = 35 ⇒ 5t₁ + 60t₂ = 35
_________________________
5t₁ + 60t₂ = 35
t₁ + t₂ = 1.5 (*-5)
5t₁ + 60t₂ = 35
-5t₁ -5t₂ = -7.5 (+)
__________________________
55t₂ = 27.5
t₂ = 27.5/55 = 0.5 h
t₁ + t₂ = 1.5 ⇒ t₁ = 1.5 - 0.5 = 1h
d₁ = 5t₁ ⇒ d₁ = 5.1 = 5 km
d₂ = 60t₂ ⇒ d₂ = 30.0.5 = 30 km
Answer:
I think true im sorry if its not
