Answer:
Step-by-step explanation:
breadth = x
length = 2x
Perimeter = 540m
2*( length + breadth ) = 540
2 *(2x + x) = 540
3x = 540/2
3x = 270
x = 270/3
x = 90 m
Breadth = 90m = 90 *100 = 9000 cm
Length = 2*90 = 180 m = 180 * 100 = 18000 cm
No.of bricks = Area of room/ area of one brick
= 9000 * 18000 / 20 * 12
= 675000 bricks
Answer:
1. x = +/- 2
- 7
2. x =
+/- 
3. n =
+/- 
Step-by-step explanation:
1. Divide both sides by 2: (x + 7)^2 = 8
Square root both sides: x + 7 = +/- 2
Subtract 7 from both sides: x = +/- 2
- 7
2. Square root both sides: x - 3 = 
Since there is a negative inside the radical, we need to have an imaginary number:
. So, 
Add 3 to both sides: x =
+/- 
3. Divide by -5 from both sides: (n - 2)^2 = -2
Square root both sides: n - 2 = 
Again, we have to use i: 
Add 2 to both sides: n =
+/- 
Hope this helps!
Answer:
(2.5, - 10 )
Step-by-step explanation:
given endpoints (x₁, y₁ ) and (x₂, y₂ ) then the midpoint is
(
,
)
here (x₁, y₁ ) = (- 16, - 12 ) and (x₂, y₂ ) = (21, - 8 ) , then
midpoint = (
,
) = (
,
) = (2.5, - 10 )
Answer:
144 km
Step-by-step explanation:
1 hour and a half hour = 90 minutes.
In 15 minutes a car travels 24 km
In 1 minute a car travels (24÷15) = 1.6 km
In 90 minutes a car travels (90×1.6)= 144 km
Ans.- 144 km
Let's start by moving all like terms to their own sides:
-18 = -3x + 6
3x = 6 + 18
3x = 24
x = 8