Area of triangle=1/2(base×height) 360=1/2((4x-2)(7x+5)) 720=(4x-2)(7x+5) FOIL the binomial 720=28x^2+6x-10 Bring 720 to the other side 28x^2+6x-10-720=0 28x^2+6x-730=0 Factor 2 out 2(14x^2+3x-365)=0 Factor 2(14x+73)(x-5)=0 x-5=0 x=5 It can't be 14x-73=0 because the length can't be negative. You're welcome.