Answer:
140,120
Step-by-step explanation:
sum of angles in a quadrilateral =360
sum of the 1st two angles=60+40=100
360-100=260
the ratio of the remaining angles 7:6
therefore:

=140
for the second angle
260-140=120
Group 'em together
a
b
−
a
+
1
−
b
a
b
−
a
=
a
(
b
−
1
)
Notice that there will be a 1 as without it it'll simply be ab
1
−
b
=
1
(
1
−
b
)
Notice that it doesn't match with the upper one... so we'll change the signs
1
(
1
−
b
)
=
−
1
(
b−
1
)
(try to multiply them now!!
Jot them down in one expression
a
(
b
−
1
)
−
1
(
b
−
1
)
You get!!!!!!
(
a
−
1
)
(
b
−
1
)
Answer
The distance from the house to the lake is (2.5 hr)*(48 mi/hr) = 120 miles. The rerurn trip would take (120 mi)/(40 mi/hr) = 3 hours. Distance equals rate times time, so the distance to the lake is 2 1/2 hours times 48 miles per hour.
I hope this helps
Answer: Just for the first page
1/2, 3/4, 3/4, 3/4, 3/4, 3/3, 4 1/4, 5
Step-by-step explanation:
Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution