Answer: Area = 6m²
Smaller number = 16
Hours = 9.6 h
Step-by-step explanation:
A rectangle is 5 meters longer than its width. If the length is shortened by 2 meters and width is increased by 1 meter, the area remains the same. Find the area of the rectangle.
1) w = x m 2) w = x + 1 m
l = x + 5 m l = x + 5 - 2 = x + 3 m
A₁ = A₂
A = w*l
A₁ = x(x+5) = x² + 5x
A₂ = (x+1)(x+2) = x² + x + 2x + 2 = x² + 3x + 2
A₁ = A₂
x² + 5x = x² + 3x + 2
5x - 3x = 2
2x = 2
x = 1
A₁ = x(x+5) = 1.6 = 6 m²
The ratio of two numbers is 2:5. If the larger number is 40, what is the smaller number.
<u> 2 </u> = <u> x </u>
5 40
5x = 80
x = 80/5 = 16
Sixteen construction workers can finish cementing a floor of a building in 3 hours. On a certain day, only 5 construction workers are available for the job. How long will it take the 5 construction workers to do the cementing job?
workers hours
16 3
5 x
↑ ↓ inversely proportional
<u> 5 </u> = <u> 3 </u>
16 x
5x = 16*3
5x = 48
x = 48/5
x = 9.6 h
X=length
y=width
Area (rectangle)=length x width
we suggest this system of equations:
y=x/5
xy=9/20
solve this system of equations by substitution method:
x(x/5)=9/20
x²/5=9/20
Least common multiple=20
4x²=9
x²=9/4
x=⁺₋√(9/4)
we have two solutions:
x₁=-3/2 it does not validate
x₂=3/2 ⇒y=x/5=(3/2)/5=3/10
The dimensions of the lake are:
lengh=3/2 miles
width=3/10 miles
to check:
Area=3/2 miles x 3/10 miles=9/20 miles².
width is 1/5 the length of the lake ⇒ 3/10 miles=(3/2) /5 miles
The answer is 56 cookies because i did math in my head
