Answer:
92 mph
Step-by-step explanation:
Let the speed of the van travelling south
=
v
mph
The distance travelled by the car travelling north is
d
1
=
10
⋅
2.5
=
25
The distance travelled by the car travelling south is
d
2
=
v
⋅
2.5
=
2.5
v
The distance between the cars after
2.5
h
is
d
1
+
d
2
=
255
25
+
2.5
v
=
255
2.5
v
=
255
−
25
=
230
v
=
230
2.5
=
92
mph
The speed is
=
92
mph
K+3=-9
k=-12 is the answer
Let 11x + 15y + 23 = 0 be equation (1)
And 7x - 2y - 20 = 0 be equation (2)
Multiply equation (1) by 2:
22x + 30y + 46 = 0
Multiply equation (2) by 15:
105x - 30y - 300 = 0
Add equations (1) and (2):
22x + 105x + 30y - 30y + 46 - 300 = 0
127x - 254 = 0
127x = 254
x = 254/127
[x = 2]
Substitute x = 2 in equation (1) to find y:
11(2) + 15y + 23 = 0
22 + 15y + 23 = 0
15y + 45 = 0
15y = -45
y = -45/15
y = -3
Therefore, x = 2 and y = -3.
