Question

(2x/5+8). (-x/5+5) =? Me ajudem por favor

Answer 1

-2x²/25+10x/5-8x/5+40      X=2+30/-4=-8    X2=2-30/-4=7
-2x²/25+2x-8x/5+40
-2x²+50X-40X+ 100
-2X²+10X+100=0
A=-2  B=10   C=100
Δ=10²-4.(-2).100
Δ=100+800
Δ=900