Answer:
A
Step-by-step explanation:
V= BxHxL divided by 2
6x9x21= 1,134
divided by 2 equals 567yd
Only the third one makes x=-1 true
Most of the square numbers are even.so if we need to find root over we need an even number to convert it to perfect square.
See the example below






Some other triplets are
- (6,8,10)
- (5,12,13)
- (8,15,17)
The second step is wrong. What should've been done is to find greatest common factor (gcf) of 1/6 and -2. This is because you cannont add together a number with a variable to a number without a variable. So get the variable by itself by subtracting 1/6 from both sides.
1/5x + 1/6 = -2
___— 1/6_— 1/6
____________
Turn -2 into a fraction and find the gcf of -2 and 6:
1/5x + 1/6 = -2
___— 1/6_— 1/6
____________
1/5x = -2/1 — 1/6 ——> 1/5x = -12/6 — 1/6
1/5x = -13/6
Then divide each side by 1/5 to get the variable by itself; remeber: when dividing a fraction by a fraction, you multiply by the reciprocal.
5/1 • 1/5x = -13/6 • 5/1
x = 65/6
Then, simplify
65/6} 10.83 or 10 83/100