3^{2} - 4 x 2 x (-1)
I know the answer is 17 but I dont know how to work this out without a calculator
Please help
Do you know BODMAS? Brackets, (Powers) Of, Division, Multiplication, Addition, Subtraction?
First evaluate anything in brackets (there aren't any), then any powers, then any multiplications and divisions (from left to right), and finally any additions and subtractions (from left to right).
I prefer "Please Excuse My Dear Aunt Sally" or "PEMDAS": first do what is inside parentheses (or brackets or any "grouping" symbols), then exponents such as $\displaystyle 3^2$, then multiplications and divisions (the order of those is not important) finally additions and subtractions. For your problem, calculate $\displaystyle 3^2= 9$ and the product (4)(2)(-1)= -8 and finally do the subtraction: 9- (-8)= 9+ 8.