If 8a−4b=20 and 4a−8b=4, then what is the value of a−b?

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

Human body temperatures have a mean of 98.20° f and a standard deviation of 0.62°. sally's temperature can be described by z = 1.4. what is her temperature? round your answer to the nearest hundredth. 99.07°f 97.33°f 99.60°f 100.45°f

1. are the corresponding angles congruent 2. find the ratios of the corresponding sides 3. is triangle jkl congruent to triangle rst? if so what is the scale factor