In this question, the speed of the dolphin is already given, but the unit is different. The speed of the dolphin is given as 40 miles per hour and it has to be converted to feet per hour.
We already know that 1 mile = 5280 feet
Then
40 mile = 5280 * 40 feet
= 211200 feet
So the speed in feet per hour will be 211200 feet per hour. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar problems without requiring any help from outside.
5x+2y=20
Substitute 0.3 for x
5(0.3)+2y=20
Multiply 5 by 0.3
1.5+2y=20
Subtract 1.5 from both sides
2y=18.5
Divide 2 on both sides
Final Answer: y= 9.25
I'm thinking this is what the problem looks like:

. The first thing to do is to move the

over to the other side because it has a common denominator with the other side. Doing that and at the same time combining them over their common denominator looks like this:

. The best way to solve for x now is to cross-multiply to get 3(4-x)=-4(x-4). Distributing through the parenthesis is 12 - 3x = -4x + 16. Solving for x gives us x = 4. Of course when we sub a 4 back in for x we get real problems, don't we? Dividing by zero breaks every rule in math that there ever was! So, yes, the solution is extraneous.
-3(x+3)=-3(x+1)-5
-3x-9=-3x-3-5
-3x-9=-3x-8
The question has no solution
Answer:
Step-by-step explanation:
trapezium
<h2>If the diagonals of a quadrilateral divide each other proportionally, then prove that the quadrilateral is a trapezium.</h2>