Answer:
Step-by-step explanation:
x-y=7
-3x+9y=-39
Divide the second equation by 3
-x +3y = -13
Add this to the first equation
x-y=7
-x +3y = -13
----------------------
0x +2y = -6
Divide by 2
2y/2 = -6/2
y = -3
Now find x
x-y = 7
x -(-3) = 7
x+3 = 7
Subtract 3 from each side
x = 4
(4,-3)
Or by substitution
x-y=7
solve for x
x = 7+y
-3x+9y=-39
Substitute y+7 in for x
-3(7+y) +9y = -39
Distribute
-21 -3y +9y = -39
Combine like terms
-21 +6y = -39
Add 21 to each side
6y = -18
Answer:
1400
Step-by-step explanation:
hope that helps <3
The picture in the attached figure
we know that
surface area=2*area of the base+perimeter*height
area of the base=area of the triangle
area of the base=3*4/2----> 6 cm²
perimeter of the base=perimeter of triangle
perimeter=3+4+5----> 12 cm
height=x cm
surface area=2*6+12*x
surface area=204 cm²
12+12*x=204
12*x=204-12
12*x=192
x=192/12
x=16 cm
the answer is16 cm
Answer:
C. 128/3 meters cubed
Step-by-step explanation:
The volume of a cylinder is denoted by:
, where r is the radius and h is the height. We know it's equal to 64, so we can set that equal to V:


We know that the sphere and cylinder have the same height and radius. However, the "height" of a sphere is actually the same as its diameter, which is twice its radius. Then, we can replace h in the above equation with 2r:



Now, the volume of a sphere is denoted by:
, where r is the radius. From above, we know that
, so we can plug this into the equation:


Thus, the answer is C.
Answer:a
Step-by-step explanation: