Question

2b + 3a = 180 ........1 and,
2b + a =100 ............2 then what is the value of a and b .

Answer 1

Given Equation is 2b + 3a = 180 ----- (1)

Given Equation is 2b + a = 100 ----- (2)

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On solving (1) & (2), we get

= > 2b + 3a = 180

= > 2b + a = 100

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2a = 80

a = 40.

Substitute a = 40 in (1), we get

= > 2b + 3a = 180

= > 2b + 3(40) = 180

= > 2b + 120 = 180

= > 2b = 180 - 120

= > 2b = 60

= > b = 30.

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Therefore, value of a = 40, b = 30.

Hope this helps!

Answer 2

here is your answer -

we have two equations and two variables so, we should proceed in the following way to solve such type of questions :

2b + 3a = 180 ---------- (1)
2b + a = 100 ------------ (2)

subtracting equation (2) from equation (1)
we get,

2a = 80
•°•, a = 40

Now, putting the value of "a" in equation (1)
we get,

2b + 3a = 180
2b + (3×40) = 180
2b = 180 - 120
2b = 60
•°•, b = 30.

so, the value of a = 40 and b = 30

hope you understand !