[tex]\sf f(x) = 2x^2 + 7x - 1[/tex]
Just substitute the value of x as (-8) .
[tex]\sf f(-8) = 2(-8)^2 + 7(-8) - 15[/tex]
[tex]\sf f(-8) = 2(64) - 7(8) - 15[/tex]
[tex]\sf f(-8) = 128 - 56 - 15[/tex]
[tex]\sf f(-8) = 128 - 71[/tex]
[tex]\sf f(-8) = 57[/tex]
