Question

Please help asap 73 pts 3 questions

Answer 1

`ax^2+bx+c=0\\\\\Delta=b^2-4ac\\\\if\ \Delta \ \textgreater \ 0\ then\ the\ equation\ has\ 2\ solutions\\if\ \Delta=0\ then\ the\ equation\ has\ 1\ solution\\if\ \Delta \ \textless \ 0\ then\ the\ equation\ has\ no\ solution\\\\x^2+9x+20=0\\a=1;\ b=9;\ c=20\\\\b^2-4ac=9^2-4\cdot1\cdot20=81-80=1 \ \textgreater \ 0\\\\\boxed{Answer:\ 2}`



`x^2-19x=x^2-2x\cdot9.5=x^2-2x\cdot9.5+9.5^2-9.5^2\\\\=(x-9.5)^2-90.25=(x-9.5)^2-90(1)/(4)=(x-9.5)^2-(361)/(4)\\\\\boxed{Answer:\ (361)/(4)}`



`quadratic;\ y=2x^2-4x\\\\check:\\for\ x=0\to y=2(0)^2-4(0)=0\ :)\\\\for\ x=1\to y=2(1)^2-4(1)=2-4=-2\ :)\\...\\for\ x=4\to y=2(4)^2-4(4)=32-16=16\ :)\\\\\boxed{Answer:\ quadratic;\ y=2x^2-4x}`