Answer:
<h3><u><em>
20y + 30</em></u></h3>
Step-by-step explanation:
Answer:
Step-by-step explanation:
Let the age be xy or 10x + y.
Reverse the two digits of my age, divide by three, add 20, and the result is my age, convert this to equation:
- (10y + x)/3 + 20 = 10x + y
- (10y + x)/3 = 10x + y - 20
- 10y + x = 3(10x + y - 20)
- 10y + x = 30x + 3y - 60
- 30x - x + 3y - 10y = 60
- 29x - 7y = 60
We should consider both x and y are between 1 and 9 since both the age and its reverse are 2-digit numbers.
Possible options for x are:
- 29x ≥ 7*1 + 60 = 67 ⇒ x > 2, at minimum value of y,
and
- 29x ≤ 7*9 + 60 = 123 ⇒ x < 5, at maximum value of y.
So x can be 3 or 4.
<h3>If x = 3</h3>
- 29*3 - 7y = 60
- 87 - 7y = 60
- 7y = 27
- y = 27/7, discarded as fraction.
<h3>If x = 4</h3>
- 29*4 - 7y = 60
- 116 - 7y = 60
- 7y = 56
- y = 8
So the age is 48.
(180 * 2) * 3 + 200 * 2
360 * 3 + 400
1080 + 400 = 1480 feet
2 times 8 x 12
192
2 times 5 x 8
80
2 times 12 x 5
60
192+80+60=332 ft^2
Answer:
d
Step-by-step explanation:
the answer is 12% decrease in area
