Number: n
square of number: n^2
sum of n and n^2 is n+n^2=20
Rewriting this equation, we get n^2+n-20=0 = (n+5)(n-4) = 0
Then n+5=0 and n-4=0, so n = -5 and n = 4.
You must check both results. It could happen that both are correct, or that only one is correct.
Answer:
x=1.714285714 or x=1.71
Step-by-step explanation:
Distribute 8 to x and 8 (8x+64)
Get rid of -13x on the other side of the equation by doing +13x to both sides.
That should leave you with 21x+64=100.
Subtract 64 from both sides of the equation.
21x=36
Divide 21 from both sides which will leave you with the answer as a long decimal so round it.
x=1.71
Answer:
61.2%
Step-by-step explanation:
Let's start by finding the total area of the circle
it says that the radius is 4 so the total area is 16π
Then let's find the area of the traingle
The hieght is 6.5 and the base is 6
.5*6.5*6=19.5
Let's then find the white area
16π-19.5=30.765
Finally we just have to do (30.765/16π)= 61.2%
answer
the number of buses is 3
the number of cars is 6
Step-by-step explanation:
total number of the students=165
total number of the vehicles=9
let x represent the number of cars
let y represent the number of buses
x+y=9...........equation 1
(the number of the cars plus the number of the buses= to the number of vehicles )
5x + 45y=165.......equation 2
(the number of student the car can hold plus the number of student the bus can hold= to the total number of the student in a class)
x+y=9.......eqn 1
5x +45y=165....eqn 2
make x the subject of the formula in eqn 1
x+y=9
x= 9-y
substitute for x= 9-y in eqn 2
5(9-y)+45y=165
45-5y+45y=165
-5y+45y=165-45
40y=120
divide both sides by 40
40y÷40=120÷40
y=3
since y represent number of buses,the numbet of bus is 3
Also,substitute for y=3 in eqn 1
eqn 1 is x+y=9
x+3=9
x=9-3
x=6
therefore,the number of cars is 6.
Answer:
See explanation
Step-by-step explanation:
William is thinking of a number n.
Then
two times his number = 2n
five less than two times his number = 2n - 5
The result is between negative three and fifteen, so

Solve this compound inequality. First, add 5:

Divide it by 2:

William's number is between 1 and 10