Please tell me what goes in the blank

It says factor each expression 49x-28?

Aquadratic equation in standard from is written ax^2= bx+c, where a, b and c are real numbers and a is not zero?

An unknown number x is at most 10. which graph best represents all the values of x? number line graph with closed circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the left. number line graph with closed circle on 10 and shading to the left.