You add or subtract, as required by the equation!
The rule is to evaluate terms according the following order of priority: In UK it is BIDMAS, an acronym for Brackets, Index, Division, Multiplication, Addition and Subtraction. In US, it is PEMDAS = Parentheses, Exponent, Multiplication, Division, Addition and Subtraction order of the mathematical order of operations." Note, that multiplication and division have the same priority; also, addition and subtraction have the same priority.
-6-85 Two signs of substraction make addition but the sign remains of subtraction -71 Hence the required answer is -71
If they are present in the expression you need to use them to evaluate the expression, if they are not, you don't. You would not use any of them - at least not explicitly - to evaluate sqrt[ln(pi)], for example.
There is no such thing as an "associative property for subtraction". In the case of addition, for example:(10 + 6) + 3 = 10 + (6 + 3)For subtraction, the following statement is incorrect:(10 - 6) - 3 = 10 - (6 - 3)Try it out - it doesn't evaluate to the same number.
order of operations:);evaluate powers first, parenthesis second, multiplication and division third (if there is a combination of the two it doesn't matter the order you evaluate), and addition and subtraction last (like multiplication-division it doesn't matter the order you evaluate these two, a helpful tool for this step is to change all minus operations to plus negative).
You didn't include division in your question, but I will include it in the answer. First, evaluate all the exponents. Second, do all the multiplications and divisions together, in order from left to right. Third, do all the additions and subtractions together, in order from left to right.
When you have mixed operations, multiplication and division precede addition and subtraction: (72/9)-(8/3) = 8 - 8/3 = 16/3 or 5 1/3 or 5.333
BIDMAS (UK) or PEMDAS (US). B or P : Brackets (Parentheses) I or E : Index (Exponent) DM or MD : Division and Multiplication. Equal priority, evaluate from left to right. AS : Addition and Subtraction. Equal priority, evaluate from left to right.
To evaluate means to find the value. Substitute the values of the variables and calculate the value. [You may need to solve for the values of the variables first.]
CPUs, when given mathematical equations, apply the laws of mathematics to those equations. The equation a = a is true by the reflexive property of equality.
5
You substitute the value of the variable into the quadratic equation and evaluate the expression.