SOLUTION: Solve equation: xy = 600 (x + 10) (y - 5) = 600 xy - 5x + 10y

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Question 1168628: Solve equation:
xy = 600
(x + 10) (y - 5) = 600
xy - 5x + 10y - 50 = 600
Not sure how to solve.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39620) (Show Source):
You can put this solution on YOUR website!
To form your exercise better, solve the system of equations:

Simplifying the second equation:

and by substitute using the first equation,

and if subtitute for x then

Continuing from that last equation, multiply left and right sides by y.

And if you try to avoid solving a quadratic equation;
and then

the factorization suggests .
You can evaluate x.

Answer by MathTherapy(10552) (Show Source):
You can put this solution on YOUR website!

Solve equation:
xy = 600
(x + 10) (y - 5) = 600
xy - 5x + 10y - 50 = 600
Not sure how to solve.

(x + 10)(y - 5) = 600 ------ eq (ii) ------- Substituting for x in eq (ii) ------- Multiplying by LCD, y (y - 20)(y + 15) = 0 y - 20 = 0 OR y + 15 = 0 y = 20 OR y = - 15 ------- Substituting 20 for y in eq (i) x = 30 ------- Substituting - 15 for y in eq (i) x = - 40

SOLUTION: Solve equation: xy = 600 (x + 10) (y - 5) = 600 xy - 5x + 10y - 50 = 600 Not sure how to solve.