You multiply a number by 3 subtract 6 then add 2 the results is 20
what's the number ?
Let the number = x
multiply a number by 3
so, it becomes 3x
subtract 6 , so, 3x - 6
then add 2
so, 3x - 6 + 2
The result will be 20
So,
3x - 6 + 2 = 20
solve for x
3x - 4 = 20
Add 4 to both sides
3x - 4 + 4 = 20 + 4
3x = 24
Divide both sides by 3
3x/3 = 24/3
So,
x = 8
Step-by-step explanation:
Answer:
9 cm.
Step-by-step explanation:
Let the height of the pyramid be h cm, then the height of the cuboid is (15 - h) cm.
Volume of the pyramid:
= 1/3 * h * s^2 where s is the length of a side of the square base.
= hs^2/3 cm^3
Volume of the cuboid:
= s^2(15 - h).
So we have:
hs^2/ 3 = 300.......................(1)
s^2(15 - h) = 600..................(2)
From equation (1) :
h s^2 = 900
s^2 = 900/h
Now substitute for s^2 in equation (2) :
(900/h)(15 - h) = 600
Multiply through by h:
900(15 - h) = 600h
13500 - 900h = 600h
1500h = 13500
h = 9 cm (answer). brainliest?
