Given that <span>Jack rakes the yard in 5 hours and Jill rakes the yeard in 8 hours. Let the amount of time that it takes them to rake the yard together be t, then:

$\frac{1}{t} = \frac{1}{5} + \frac{1}{8} \\ \\ = \frac{8+5}{40} = \frac{13}{40} \\ \\ \therefore t= \frac{40}{13} =3 \frac{1}{13}\ hours$ </span>

8 0

3 years ago

What's substitution for:<br> X=y-7<br> X+8y=2

MrRissso [65]

$\left \{ {{x=y-7} \atop {x+8y=2}} \right. \\\\
substitute\ x=y-7\ into \ the\ second\ equation\\\\
y-7+8y=2\\\\
9y-7=2\ \ \ | add\ 7\\\\
9y=9\ \ \ | divide\ by\ 9\\\\
y=1\\\\x=y-7=1-7=-6$

4 0

3 years ago

Side c is the hypotenuse. Sides a and b are the legs. 6. b = 6 yd, c = 4 yd. Find the missing side.

balandron [24]

Answer:

2.6666

Step-by-step explanation:

hypotenuse is c^2 so you square 4 to get 16 and then you divide it by 6 to 2.666 so that is the answer for the other leg

7 0

3 years ago