Question 1011637
Your left-side expression,  1+2×3+4×5+6


PEMDAS, Parentheses, Exponents, Multiplication, Division, Addition, Subtraction, those being the order of precedence.


Your precedences start with Multiplications.  Do those first.


1+6+20+6


You next have only Additions, and nothing else.  Go strictly from left to right.
7+20+6
27+6
33