Question

evaluate f(x)=2x^2-3x+4 at x=7 and x=-2​

Answer 1

Answer:

f(7)=2(49)-3(7)+4

=98-25

= 73

f(-2)= 2(4)+3(-2)+4

=. 8-6+4

=. 6

Answer 2

Given:

f(x)=2x²-3x+4

To Find:

Evaluate f(x)=2x²-3x+4 at x=7 and x=-2​

Solution:

In the given question we have to solve f(x)  when x is 7 and when x is -2

For that we will put the value of x =7 in the equation,  f(x)=2x²-3x+4

According to the question:

When x = 7

f(x)=2x²-3x+4

f(7) = 2(7)² -3(7) +4

f(7) = 2× 49 - 21 +4         [∵7² = 49]

f(7) = 98 -21 +4

f(7) = 77+4

f(7) = 81

Now,

When x = -2

f(x) = 2x²-3x+4

f(-2) = 2(-2)² - 3(-2) +4

f(-2) = 2×4 +6 + 4             [∵-3×-2 = 6 ]

f(-2) = 8+6+4

f(-2) = 18

Hence, the value of f(x) at x = 7 and x = -2 is 81 and 18 respectively.