You want to use PEMDAS for this.
<em>P</em>= arenthesis ( )
<em>E</em>= xponents a²
<em>M</em>= ultiply ×
<em>D</em>= ivide ÷
<em>A</em>= dd +
<em>S</em>= ubtract -
What you want to do is go in order and ask yourself as you go.
Are there any <u><em>Parenthesis</em></u>? <em>No
</em>Are there any <u><em>Exponents</em></u><em />? <em>No</em>
Is there any <em /><u><em>Multiplication</em></u><em />? <em>Yes
</em><em />Is there any <em><u>Division</u></em>? <em>No
</em><em />Is there any <em><u>Addition</u></em>? <em>No
</em><em />Is there any <em><u>Subtraction</u></em><u />? <em>Yes</em><em>
</em><em />Thats when you stop and you multiply what you have in the PEMDAS. Top to bottom. 3x5 which gives you 15. Now you equation is 45-15. Thats when you subtract and you get your answer which is 30.
Answer:
AB = -10
Im confused is this what you wanted?
N=25 because 20 divided by 4 is 5 which is 1/5 of n meaning 5x5 is 25
