Step-by-step explanation:
EF = 4x - 15
FG = 3x - 7
EG = EF + FG = 20
so,
4x - 15 + 3x - 7 = 20
7x - 22 = 20
7x = 42
x = 6
EF = 4×6 - 15 = 9
FG = 3×6 - 7 = 11
Answer: 56
Step-by-step explanation: first, you have to find the area of one triangle. The formula is A=bh1/2 . When you do that, you get 14. 14 is only one triangle, so multiply it by 4 and you get your answer, 56.
Let:
Vj = Speed of jane
Vm = Speed of mike
d = distance
t = time
Jane travels 7 mph less than 2 times as fast as Mike, therefore:
Vj = 2Vm - 7
Remeber:
distance = speed*time
Distance traveled by mike:
d=Vm*t = Vm*6
Distance traveled by jane:
d + 198 = Vj*6
where:
Vj = 2Vm - 7
d + 198 = (2Vm-7)*6
Now, let:
d=Vm*6 (1)
d + 198 = (2Vm-7)*6 (2)
Replace (1) into (2)
6Vm + 198 = 12Vm - 42
Subtract 6Vm from both sides:
6Vm + 198 - 6Vm = 12Vm - 42 - 6Vm
198 = 6Vm - 42
Add 42 to both sides:
198 + 42 = 6Vm - 42 + 42
240 = 6Vm
Divide both sides by 6:
240/6 = 6Vm/6
40 = Vm
Vm = 40mph
Replace Vm into this equation Vj = 2Vm - 7 :
Vj = 2(40) - 7 = 80 - 7 = 73mph