Answer: 58.42
Formula: Multiply the length value by 2.54
23×2.54
=58.42
12 Inches = 30.48 Centimetres
1.

or if you mean (3x^3+5x^2+3x-7)+(8x-6x^2+6):

2.

This is the expression simplified:
Get them to have a common denominator so you can add them
(1/3)×2= 2/6 and (1/2)×3= 3/6
Add them together
(2/6)+ (3/6)= 5/6
So 5/6 of the class planted either marigolds or tulips and 1/6 of the class planted neither
Answer: x³+y³=180
Step-by-step explain: let's remember the formula x³+y³=(x+y)(x²-xy+y²) and also x³+y³=(x+y)³-3xy(x+y) then