What’s the value for Y

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

One of the solutions to x2 - 2x – 15 = 0 is x = -3. what is the other solution? ox=-5 ox= -1 0 x=1 x = 5

Find the radius of a circle that has a circumference of 16. the formula for the circumference of a circle is c = 2tr, where r is the radius and c is the circumference. the equation solved for r is r = c over 2π. r=4 r= 8 r=12 r= 16