This is a Fibonacci sequence
1; 1
1 + 1 = 2
1 + 2 = 3
2 + 3 = 5
3 + 5 = 8
next terms:
5 + 8= 13
8 +13 = 21
13 + 21 = 34
Answer:
Step-by-step explanation:
xy = 300
x + y = 50 Solve for y
y = 50 - x substitute into xy = 300
x(50 - x) = 300 Remove the brackets.
50x - x^2 = 300 Bring the left to the right.
0 = x^2 - 50x + 300
This is a quadratic. It will have 2 solutions.
a=1
b = - 50
c = 300
Put these into the quadratic equation.
It turns out that x has two values -- both plus
x1 = 42.03
x2 = 6.97
x1 + y1 = 50
42.03 + y = 50
y = 50 - 42.03
y = 7,97
(42.03 , 7.97)
====================
x2 + y2 = 50
6.97 + y2 = 50
y2 = 50 - 6.97
y2 = 43.03
(6.97 , 43.03)
How about raising 286 up by 14 to 300 and compensating by lowering 428 by the same 14 Since I know that 14 + 14 is 28 then 28-14 is 14
So 428 - 14 = 414
So now I have 414 + 300 which I can do mentally - the answer is 714 and is also the answer to the original problem 428 + 286
Compensation works very well - bring one number up or down to a rounded number and compensate by doing the opposite to the other - instead of 199 + 457 - try 200 + 456
Same answer and because one of the numbers is nicely rounded, it is easy to add the other.
One more: 207 + 182 becomes 200 + 189 =389 I lowered one by 7 and raised the other one by the same 7.
