Call the numbers A and B.

If a number is 3 less than another number

then the larger number minus the smaller number equals 3

So we have ...

A - B = 3 ... and ... A + B = 297

Combine the two together ...

A - B = 3 and A + B = 297 gives you ..

A + A - B + B = 297 + 3

2A = 300

A = 150

and so B = (150 - 3) = 147

The numbers are (297 - 3)/2 = 147 and (297 + 3)/2 = 150.

x + y = 297  x - y = 3 

The numbers are 150 and 147.

A number is 3 less than another number.

The sum of the numbers is 297.

x + y = 297

x - y = 3

The numbers are 150 and 147.

:-

x = y - 3

y = x + 3

x + y = 297

x + x + 3 = 297

2x = 294

x = 147

y = 150

Method 1:

Let a and b be the two numbers, where a > b.

a = b + 3 …… [1]

a + b = 297 ……. [2]

Substitute [1] into [2]:

(b + 3) + b = 297

2b = 294

b = 147

Substitute b = 147 into [1]:

a = 147 + 3

a = 150

The two numbers are 147 and 150.

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Method 2:

Let y be the smaller number.

Hence, the greater number = y + 3

y + (y + 3) = 297

2y = 294

y = 147

y + 3 = 150

The two numbers are 147 and 150.

2a+3 = 297

a = 294/2 = 147

b = a+3 9 150

If its 3 less, then both numbers are close to each other, right? They are almost the same, right? IOW, if you add both "same" numbers, you get 297. 

Thus one of the numbers is roughly half of 297. This is roughly half of 300, which is 150.

So try 147 & 150. Do they work? If not, try 147 & 149. Etc. 

Whats your final answer?