How do you solve the system of equations $5x + 4y = 60$ and $8x + 7y = 99$ ?

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Answer 1 · 2018-07-02T08:57:32

$color(red)(x = 8, y = 5$

$5x + 4y = 60, " Eqn (1)"$

$8x + 7y = 99, " Eqn (2)"$

$7 * " Eqn (1)" - 4 * " Eqn (2)"$

$35x + 28y - 32x - 28y = 420 - 396$

$3x = 24 " or x = 8$

Substituting value of 'x' in Eqn (1),

$5 * 8 + 4 y = 60$

$y = (60 - 40) / 4 = 5$

How do you solve the system of equations 5x + 4y = 605x + 4y = 60 and 8x + 7y = 998x + 7y = 99?