Answer:


Step-by-step explanation:
2x² +21x-61 = (x+7)²
expand
2x² + 21x - 61 = x² + 14x +49
move everything to one side
x² + 7x - 12 = 0
use quadratic formula

plug in the values

solve



14 3/5 as a decimal would be 14.6
See the attached picture for the solution:
Diagonal of a square is √2a
so,
√2 a = 12
a= 12/√2
and.. perimeter of a square is 4a
so,
peri = 4*12/√2
= 48/√2
=33.94cm
The time for the job for which the two company are the same is 16
<h3>How to form the equation and find the cost?</h3>
A yard cleanup service charges a $345 fee plus $16.25 per hour. Therefore,
using linear equation,
y = mx + c
where
Therefore,
y = 345 + 16.25x
Another cleanup service charges a $213 fee plus $24.50 per hour. Therefore,
y = 213 + 24.50x
Hence, the time when both cost are the same is as follows;
213 + 24.50x = 345 + 16.25x
213 - 345 = 16.25x - 24.50x
-132 = -8.25x
x = 132 / 8.25
x = 16
learn more on equation here: brainly.com/question/2072580