The mass of an oxygen molecule is 5.31 x 10-23 grams. The mass of a helium-4
atom is 6.65 x 10-24
grams. How many times greater is the mass of an oxygen
molecule than the mass of a helium-4 atom? Write your answer in standard notation,
rounding to the nearest tenth.

What is the value of x? enter your answer in the box. (cm)

Use addition and subtraction to simplify the following polynomials. a. add polynomials: (3 – 4x + 8x^2) + (–6 + 2x – 5x^2) step 1: rewrite the polynomials without the parentheses. step 2: write the polynomial in descending order and use parentheses around like terms. step 3: add the like terms identified in step 2 to simplify the polynomial. b. subtract polynomials: (3x – 5 – 7x^2) – (–2 + 6x^2 – 5x) step 1: rewrite the polynomials without the parentheses. remember to multiply each term in the second parentheses by –1. show your work. step 2: write the polynomial in descending order and use parentheses around like terms. step 3: add the like terms identified in step 2 to simplify the polynomial.

Find the perimeter of the figure shown above. a. 40 cm c. 52 cm b. 60 cm d. 75 cm select the best answer from the choices provided