Good evening.
This is a
incomplete quadratic equation, because it does not have the term
bx. Therefore, we can solve this faster with the following strategy:

Add
16 to both sides:

Take the square root:

Therefore:
The distance across the lake, a is 611 yards
<h3>Right angle triangle:</h3>
Right angle triangle have one of its angles as 90 degrees. Therefore, the side a can be found using trigonometric ratios,
Therefore,
tan 47° = opposite / adjacent
tan 47° = a / 570
cross multiply
a = 570 tan 47°
a = 570 × 1.07236871002
a = 611.250164714
a = 611 yards
learn more on right triangle here: brainly.com/question/18450490
<h2>218 = 49 + 169 = 7² + 13² </h2><h2><u>218 = 7² + 13²</u> </h2><h2> </h2><h2> </h2><h2> </h2><h2 />
Answer:
-7.5x3+(20+2.5)=0
this one is equal to 0 ;)