Answer:
x= -2 y= -1
Step-by-step explanation:
stack the 2 equations on top of each other and add them together
the 2x and -2x cancel out and you are left with -9y=9
this gives you y= -1
you plug the y value into one of the equations:
2x - (-1) = -3
2x+1 = -3
2x= -4
x= -2
Remark
The proof is only true if m and n are equal. Make it more general.
m = 2k
n = 2v
m + n = 2k + 2v = 2(k + v).
k and v can be equal but many times they are not. From that simple equation you cannot do anything for sure but divide by 2.
There are 4 combinations
m is divisible by 4 and n is not. The result will not be divisible by 4.
m is not divisible by 4 but n is. The result will not be divisible by 4.
But are divisible by 4 then the sum will be as well. Here's the really odd result
If both are even and not divisible by 4 then their sum is divisible by 4
Answer:
length = 78 feet
width = 36 feet
Step-by-step explanation:
Using one variable and an expression, you can set up an equation equal to the perimeter to find the measure of each side:
width = 'w'
length = '42ft longer than it was wide' = w + 42
The general formula for the perimeter of a rectangle:
P = 2w + 2l
Plugging in the given values and variables:
228 = 2w + 2(w + 42)
Distribute: 228 = 2w + 2w + 84
Combine like terms: 144 = 4w
Divide and solve: 36 = w
w = 36 ft
l = 36 + 42 = 78 ft
Answer:
43.8 km to the nearest tenth.
Step-by-step explanation:
5 miles is 8 km
so 1 mile = 8/5 km
and 27.4 miles = 27.4 * 8/5
= 43.84 km
Standard: x=4
implicit: x-4=0
