Answer:
4. C. x = 4 or -4
Step-by-step explanation:
since both terms are perfect squares, factor using the difference of squares formula, a² - b² = ( a + b ) (
- b ) where
X represents the number that would be added to the silver cars.
x/40= 4
X=40x4
x=160
Subtract the given 20 from 160 because 160 is the total number
160-20=140
Therefore 140 would be added to 20 silver cars to get the ratio1:4
30, you can devide 135 by 4.5
6/10 its adjacent over hypotenuse