solve the simuteneous equation.a+2b=13,2a-3b=5
4 answers
solve
...
using calculater...
using calculater...
a=7 b=3
Without a calculator.
eqn 1 is a+2b=13
eqn 2 is 2a-3b= 5
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Multiply eqn 1 by -2, add to eqn 2 and solve for b as follows:
-2a -4b = -26
2a -3b = 5
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-7b = -21
b = -21/-7 = 3. Now substitute 3 for b in eqn 2 and solve for a as follows:
2a - 3b = 5
2a -3*3 = 5
2a = 5+9 = 14
a = 14/2 = 7
So a is 7 and b is 3.
eqn 1 is a+2b=13
eqn 2 is 2a-3b= 5
-------------------------
Multiply eqn 1 by -2, add to eqn 2 and solve for b as follows:
-2a -4b = -26
2a -3b = 5
------------------------
-7b = -21
b = -21/-7 = 3. Now substitute 3 for b in eqn 2 and solve for a as follows:
2a - 3b = 5
2a -3*3 = 5
2a = 5+9 = 14
a = 14/2 = 7
So a is 7 and b is 3.
2 answers