Which of the following is a possible cause for eutrophication? (a) over fishing of a local water supply (b) use of biodegradable products (c) sewage runoff (d) use of riparian buffer zones
(c) sewage runoff Eutrophication is the reduction of oxygen in a given body of water. Sewage runoff will increase nitrates in the water (much like fertilizer runoff). This promotes vegetation growth. This growth if untreated can cause a water source to no longer have the necessary oxygen to support life; producing a dead zone.
Which of the following is an example of an sedimentary rock? (A) limestone (B) granite (C) marble (D) obsidian
(A) limestone Limestone is the only sedimentary rock listed, it is formed through either organic or inorganic means. Although marble is the metamorphosed version of limestone, characteristics of the stone, and thus classification, have changed.
Suppose, x²+7x+12=0, factor the expression:
To begin factoring this quadratic you need to find factors of 12 that add up to 7. 3*4=12, 3+4=7 Next you will need to rewrite the expression within parenthesis: (x+3)(x+4)=0 An easy way to check you answer is to FOIL, (First, Outside, Inside, Last) x(x)+4x+3x+3(4)=0 x²+7x+12=0 Therefore; (x+3)(x+4)=0 will be your completed factoring. With this information you can further graph your quadratic.