If measure angle 1 equals 7x and measure angle 4 equals 3x+20, what is the value of x?

You have 6 dollars +12 pennies +to quarters + 4 dimes=2 nickels how much do you have

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?