Question

The function f(x) = 2x^2 + 3x + 5, when evaluated, gives a value of 19. What is the function’s input value?
A. 1
b. -1
C. 2
D. -2
E. -3

Answer 1

have you substituted any values to check them...?

Answer 2

as an example x= 1

y = 2(1)^2 + 3(1) + 5 = 10

so its not x = 1

Answer 3

o that's all i have to do?

Answer 4

yep

Answer 5

@campbell_st im lost i thought i had it but i dont

Answer 6

ok so the next value is x = -1

substitute that

y = 2(-1)^2 + 3(-1) + 5 you need a little care here as squaring a negative gives a
positive

so

y = 2 - 3 + 5

y = 4

so it't not x = -1

just repeat the process

Answer 7

ok thanks