Exercise 1 - fill in the missing words in the sentences below.

1. The mass of the reactants (starting chemicals) is E- to the mass of the products (the chemicals that are made).

2. The products have different P- to the reactants.

3. During a chemical reaction Heat is either taken in or given out.

4. A chemical change is difficult to R - (go backwards).

The angles below are supplementary. what is the value of x? a pair of supplementary angles is shown. one angle measures 7x + 33, and the other angle measures 70. 5.3 8.14 11 14.7

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota