Answer:
x > 7/4
Step-by-step explanation:
3(x + 7) < 7(x + 2)
Expand brackets: 3x + 21 < 7x + 14
Subtract 14 from both sides: 3x +7 < 7x
Subtract 3x from both sides: 7 < 4x
Divide both sides by 4: 7/4 < x
Therefore x > 7/4
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
Answer:
0.35, 0.40
Step-by-step explanation:
