Answer:
a=3x+b/4-x
Step-by-step explanation:
I dont know which variable you're supposed to solve for. But here's how i got the answer above:
Divide each term in a(4-x)=3x+b by 4-x
a(4-x)/4-x=3x/4-x+b/4-x
Then, cancel the common factor of 4-x, giving you
a=3x/4-x+b/4-x
Finally, combine the numerators over the common denominator,
giving you a=3x+b/4-x
Perpendicular = opposite sign and reciprocal slope
Make equation into y = mx + b
Add 3y to both sides
3y + 54 = 3x
Subtract 54
3y = 3x - 54
Divide by 3
y = x - 18
The slope is 1
Make it negative and reciprocal
= -1/1 = -1
Solution: the slope will be -1
You could estimate by doing 600x3=1800
(becasuse of the 0's in 600 it is easier to do 6*3=18 and then add two 0's to the end 1800)
then you simply multiple 640x3=1920
