The perimeter =14 in
The area =64cm
Answer:
450 feet
Step-by-step explanation:
60ft = 4 seconds
x ft = 30 seconds
(cross multiply)
60 * 30 = 4x
1800= 4x
(divide both sides by 4)
x= 1800/4= 450
Call the two equations above A and B, in order to not confuse them.
A: -2x + 6y = -38
B: 3x - 4y = 32
For this system we have opposites in x and y, so Elimination (or Linear Combination) works best. Either variable works, so let's work with x first and multiply A by 3 and B by 2. This is done so we get opposites in A and B then when added together give zero.
-2x + 6y = -38 ------> multiply by 3 ----> -6x + 18y = -114
3x - 4y = 32 ------> multiply by 2 -----> 6x - 8y = 64
Now we add the new equations. The -6x and 6x are opposites and go away. We are left with
10y = -50. We divide both sides by 10 and get that y = -5.
Now we take y = -5 and put it into an original equation. Let's use A.
-2x + 6y = -38 the original equation A
-2x + 6(-5) = -38 we found y = -5
-2x + (-30) = -38 evaluating and multiplying
-2x - 30 = -38 apply the parentheses
-2x = -8 add 30 to both sides
x = 4 divide on both sides by -2
Thus x = 4 and y = -5, or (4, -5) is the solution.
Answer:
Step-by-step explanation:
Given that every day at noon, a bus leaves for Townville and travels at a speed of x kilometers per hour. Today, the bus left 30 minutes late.
If the driver drives 7/6 times as fast as usual, she will arrive in Townville at the regular time.
If correct time leaves then distance = time *speed
280 = t*x where t is the time in hours
Or t = 280/x
Now speed changes to 7x/6 while time changes to (t-1/2)
So 280 = (t-1/2) 7x/6
x = 80 km per hour
