Question

Calcule 25/(x-5) = (x+30)/(x+10)

Answer 1

25/(x-5)=(x+30)/(x+10)
25(x+10)=(x+30)(x-5)
25x+250=x²+30x+x²-5x
-x²-x²-30x+5x+25x=-250
-2x²-25x+25x=-250
-2x²=-250 (-1)
2x²=250
x²=250/2
x²=125
x=±✓125
x=±5✓5