We have to use PEMDAS for this expression.
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction
(2x^2 - 5x + 4) Original Mathematical Expression
[2(7)^2 - 5(7) + 4] Plugging the value of x, 7 into expression.
There are parentheses, so that means we have to work in them.
There are exponents, so we have to do those first.
[2(49) - 5(7) +4] Exponents.
There is multiplication, that we can do, so we do that left to right.
[98 - 35 + 4] Multiplication.
There is no division.
There is addition and subtraction, so we do those left to right.
[63 + 4] Subtraction.
67 Addition.
Final Answer: 67