Slope-intercept form:
y = mx + b        "m" is the slope
First i would isolate the "y" in the equation.
2x + y = 4       Subtract 2x on both sides
2x - 2x + y = 4 - 2x
y = 4 - 2x    or     y = -2x + 4
The given line's slope is -2.
For lines to be perpendicular, their slopes have to be the opposite/negative reciprocals (flipped sign and number)
For example:
slope is 2
perpendicular line's slope is -1/2
slope is -2/3
perpendicular line's slope is 3/2
The given line's slope is -2, so the perpendicular line's slope is 1/2.
The 3rd option is your answer
 
        
             
        
        
        
Answer:
Just use long subtraction by expanding the decimal places of the whole number. This is done by adding a point, and enough zeros to it to match the number of decimal digits in the other number (digits after the decimal point). 
 12345678 
i.e: 5 - 2.48374827, 2.48374827 has 8 decimal digits, so add 8 zeros after the point.
= 
 1 1 1 1 1 1 1 
 5.00000000
 -
 2.48374827
_______________
 2.51625173
7 + 3 = <u>1</u>0, 7 + 2 + <u>1</u> = <u>1</u>0, 8 + 1 + <u>1</u>= <u>1</u>0, 5 + 4 + <u>1</u> = <u>1</u>0, 2 + 7 + <u>1</u> = <u>1</u>0, 3 + 6 + <u>1</u> = <u>1</u>0, 1 + 8 + <u>1</u> = <u>1</u>0, 5 + 4 + <u>1</u> = <u>1</u>0, 2 + 2 + <u>1</u> = <u>5</u><u> </u><u>:</u><u> </u>5.00000000
This is basically borrowing a group of 10s which are the same as 1s in the next decimal place up.
For each digit except the first to the right, let 10 subtract that number from it and minus 1 since the 1 is carried over.
 
        
             
        
        
        
Answer:
The angles are 26 and 64
Step-by-step explanation:
When two angles are complementary, what this means is that the add up to 90 degrees 
Now, let’s say one of the angles is x, the other angle is 12 more than twice it; mathematically that would be 2x + 12
Since they add up to be 90, we have
x + 2x + 12 = 90
3x + 12 = 90
3x = 90-12
3x = 78
x = 78/3
x = 26 
The other angle is 2x + 12 = 2(26) + 12 = 52 + 12 = 64
 
        
             
        
        
        
Answer:
6
Step-by-step explanation:
3x+6+5x+10=64
3x+5x+6+10=64
8x+16=64
8x=64-16
8x=48
divide both sides by 8
x=6