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A number is thrice the other number and their sum is 80. (i) Express the above statements in the form of linear equations. (ii) Find the numbers.​

User Adharsh M
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So, let us call our numbers a and b.

Statement 1:
a is thrice to b or: a = 3*b

Statememt 2:
Their (a’s and b’s) sum is 80: a+b =80

Together we have the two linear equations:
a=3b
a+b=80

Solving them can be done by using the fact that a is equal to 3b and plugging this into the second equation:

3b + b = 80


Now 3 apples plus 1 apple is 4 apples, right? So 3b + b = 4b !

4b = 80

No we divide by 4 and get the result for b:

b = 20

Now how do we find a? Well we know that a = 3b. So we just plug the solution for b into this equation:

a = 3 * 20 = 60.

That means the two numbers were 20 and 60
User Mikerowehl
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