Question:
The square of a number decreased by 3 times the number is 28 find all possible values for the number
Answer:
The possible values of number are 7 and -4
Solution:
Given that the square of a number decreased by 3 times the number is 28
To find: all possible values of number
Let "a" be the unknown number
From given information,
square of a number decreased by 3 times the number = 28


Let us solve the above quadratic equation


Using the above formula,


Thus the possible values of number are 7 and -4
The perimeter of a rectangle = 2(l + w)
l = length
w = width
In this problem,
w = x
l = x + 30
the perimeter = 148
Let's plug our values into the perimeter formula above.
148ft = 2(x + x + 30ft)
Combine like terms.
148ft = 2(2x + 30ft)
Distribute the 2
148ft = 4x + 60
Subtract 60 from both sides
88ft = 4x
Divide both sides by 4
22ft = x
The width = x = 22ft
The length = x + 30 = 22 + 30 = 52ft
The answer I got was x= 21/2
He can ride his bike 105 km. 30/2 is 15. 15*7 is 105.
:D