Which shows equivalent expressions? a squared + 3 b minus 2 a squared = 3 a squared + 3 b minus 4 a squared
a squared + 3 b minus 2 a squared = 3 a squared + 4 b minus 4 a squared
Negative a squared + 3 b minus 2 a squared = 3 a squared + 3 b
Negative a squared + 3 b + 2 a squared = 3 a squared + 4 b minus 2 a squared

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)

Is laundry detergent an acid or a base?

Which of the following has expanded our knowledge of the universe beyond our solar system the most? a. manned space travel b. the hubble space telescope c. the pioneer and voyager missions d. the international space station