Question 269013
20x+31y=332.42 multiply by -2 & add.
40x+26y=486.70
-40x-62y=-664.84
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-36y=-178.14
y=-178.14/-36
y=29.69/6 ans.
20x+31(29.69/6)=332.42
20x+920.39/6=332.42
20x=332.42-920.39/6
20x=(1,994.52-920.39)/6
20x=1,074.13/6
x=(1,074.13/6)/20
x=(1,074.13/6)1/20
x=1,074.13/120 ans.
Proof:
40(1,074.13/120)+26(29.69/6)=486.7
42,965.2/120+771.94/6=486.7
358.0433+128.6567=486.7
486.7=486.7