Answer:
46
Step-by-step explanation:
[tex]f(x) = 5x^2 + 3x - 8\\x =3\\\\= 5(3)^2+3(3)-8\\\mathrm{Follow\:the\:PEMDAS\:order\:of\:operations}\\\\\mathrm{Calculate\:exponents}\:\left(3\right)^2\::\quad 9\\=5\cdot \:9+3\left(3\right)-8\\\\\mathrm{Multiply\:and\:divide\:\left(left\:to\:right\right)}\:5\cdot \:9\::\quad 45\\=45+3\left(3\right)-8\\\\\mathrm{Multiply\:and\:divide\:\left(left\:to\:right\right)}\:3\left(3\right)\::\quad 9\\=45+9-8\\\\\mathrm{Add\:and\:subtract\:\left(left\:to\:right\right)}\:45+9-8\:\\:\quad 46[/tex]
