I:2x – y + z = 7
II:x + 2y – 5z = -1
III:x – y = 6
you can first use III and substitute x or y to eliminate it in I and II (in this case x):
III: x=6+y
-> substitute x in I and II:
I': 2*(6+y)-y+z=7
12+2y-y+z=7
y+z=-5
II':(6+y)+2y-5z=-1
3y+6-5z=-1
3y-5z=-7
then you can subtract II' from 3*I' to eliminate y:
3*I'=3y+3z=-15
3*I'-II':
3y+3z-(3y-5z)=-15-(-7)
8z=-8
z=-1
insert z in II' to calculate y:
3y-5z=-7
3y+5=-7
3y=-12
y=-4
insert y into III to calculate x:
x-(-4)=6
x+4=6
x=2
so the solution is
x=2
y=-4
z=-1
Answer:
.
Step-by-step explanation:
Use the app that you can easily find answers on
Answer:
<h2>
the answer is</h2><h2>
166 cm²</h2>
Step-by-step explanation:
we know that
surface area of the prism=2*area of the base+perimeter of the base*height
step 1
find the area of the base
area of the base=length* width
length=5 cm
width=4 cm
area of the base=5*4-----> 20 cm²
step 2
find the perimeter of the base
perimeter=2*[length+width]-----> 2*[5+4]----> 18 cm
step 3
height=7 cm
step 4
find the surface area
surface area of the prism=2*area of the base+perimeter of the base*height
surface area of the prism=2*20+18*7----> 166 cm²
their relative speed is 4 mph. so we put
4 mph = (25 mi)/x => x=25/4.
