Answer:The surface area of the cube is 100 cm.
Step-by-step explanation:
So since a cube has six faces and all of its lengths are equal. we could use the equation.
10^2 *6= 100 *6= 600
Find an equation of the plane that contains the points p(5,−1,1),q(9,1,5),and r(8,−6,0)p(5,−1,1),q(9,1,5),and r(8,−6,0).
topjm [15]
Given plane passes through:
p(5,-1,1), q(9,1,5), r(8,-6,0)
We need to find a plane that is parallel to the plane through all three points, we form the vectors of any two sides of the triangle pqr:
pq=p-q=<5-9,-1-1,1-5>=<-4,-2,-4>
pr=p-r=<5-8,-1-6,1-0>=<-3,5,1>
The vector product pq x pr gives a vector perpendicular to both pq and pr. This vector is the normal vector of a plane passing through all three points
pq x pr
=
i j k
-4 -2 -4
-3 5 1
=<-2+20,12+4,-20-6>
=<18,16,-26>
Since the length of the normal vector does not change the direction, we simplify the normal vector as
N = <9,8,-13>
The required plane must pass through all three points.
We know that the normal vector is perpendicular to the plane through the three points, so we just need to make sure the plane passes through one of the three points, say q(9,1,5).
The equation of the required plane is therefore
Π : 9(x-9)+8(y-1)-13(z-5)=0
expand and simplify, we get the equation
Π : 9x+8y-13z=24
Check to see that the plane passes through all three points:
at p: 9(5)+8(-1)-13(1)=45-8-13=24
at q: 9(9)+8(1)-13(5)=81+9-65=24
at r: 9(8)+8(-6)-13(0)=72-48-0=24
So plane passes through all three points, as required.
Answer:
b. 3
Step-by-step explanation:
20-17=3
Step-by-step explanation:
1)X represents the time he spent in cardio.
Y represents the time he spent in weighted.
2)If you could put the options on the second one it would be better.
3)4x+y=210
3x+2y=195
y=210-4x
3x+2(210-4x)=195
3x+420-8x=195
5x=420-195
5x=225
x=45
y=30
Total time of one cardi and weighted = 75min= 5/4 h.
4)2x+4y=
90+120=210 total time of week three.
