Anumber is 20 less than its square. find all such numbers.

Describe the relationship between the angles of similar triangles and the sides of similar triangles

Statements reasons 1. ab ? cd; ad ? bc 1. given 2. ac ? ac 2. reflexive property 3. ? adc ? ? cba 3. ? 4. ? dac ? ? bca; ? acd ? ? cab 4. cpctc 5. ? dac and ? bca are alt. int. ? s; ? acd and ? cab are alt. int. ? s 5. definition of alternate interior angles 6. ab ? cd; ad ? bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?

Suppose 38 lbs of coffee beans are required to produce 2 lbs of farmer's coffee. how many lbs of coffee beans are required to produce 309 lbs of farmer's coffee?