Question

(4х+3х)(5-х)-х^2=8х+19

Answer 1

(4х+3х)(5-х)-х²=8х+19

20х-4х²+15х-3х²-х²=8х+19

-8х²+27х-19=0 |*(-1)

8x²-27x+19=0

D=729-4*8*9=729-288=441=21²

x(1)=(27+21)/16=48/16=3

x(2)=(27-21)/16=6/16=3/8=0.375