How do you solve the system of equations $9 x - 2 y = 25$ $9x - 2y = 25$ and $4 x - 5 y = 7$ $4x - 5y = 7$ ?

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Answer 1 · 2018-08-06T02:43:16

$x = 3, y = 1$ $color(maroon)(x = 3, y = 1$

$9 x - 2 y = 25$ $9x - 2y = 25$ Eqn (1)

$4 x - 5 y = 7$ $4x - 5y = 7$ Eqn (2)

$36 x - 8 y - (36 x - 45 y) = 100 - 63, Eqn (1) * 4 - Eqn (2) * 9$ $36x - 8y - (36x - 45y) = 100 - 63, color(red)(" Eqn (1) * 4 - Eqn (2) * 9 "$

$- 8 y + 45 y = 37$ $-8y + 45y = 37$

$37 y = 37 or y = 1$ $37y = 37 " or " y = 1$

Substituting value of y in Eqn (1),

$9 x - 2 \cdot 1 = 25$ $9x - 2 * 1 = 25$

$9 x = 25 + 2 = 27$ $9x = 25 + 2 = 27$

$9 x = 27 or x = \frac{27}{9} = 3$ $9x = 27 " or " x = 27/9 = 3$

How do you solve the system of equations 9x−2y=259x - 2y = 25 and 4x−5y=74x - 5y = 7?