Y=-2x-5 y=4x+1how many solutions? math not geography sorry.

As water is cooled from 4 c to 0 c its density

Where the main factor that enabled the growth of cities and civilizations was the existence of

To solve this system of equations by elimination, what operation could be used to eliminate the y-variable and find the value of x? 6x + 5y = 2 4x + 2y = 8 a) subtract 2 times the second equation from 3 times the first equation b) subtract 3 times the second equation from 2 times the first equation c) subtract 5 times the second equation from 2 times the first equation d) subtract 2 times the second equation from 5 times the first equation