Question

solve
by elimination method.
2x+3y = 42 and 5x-y = 20
step by step explanation​

Answer 1

Elimination method

It implies to eliminate the cofficient of x or y Then find the value of x or y and substitute once again in the equation

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$\: \: \: 2x + 3y = 42\\ \: \: \: \: \: 5x - \: y = 20$

Multiply the second equation by 3

$2x + 3y = 42 \\ 15x - 3y = 60 \\ - - - - - - - - \\ 17x = 102 \\ x = \frac{17}{102} \\ x = 6$

Now substitute this in first equation

$2 \times 6 + 3y = 42 \\ 3y = 42 - 12 \\ 3y = 30 \\ y = \frac{30}{3} \\ y = 10$

Therefore x=6,y=10