How can i figure out the answer to 7+5=_+6

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

If c(x) = 4x – 2 and d(x) = x2 + 5x, what is (cxd)(x)

Simone claims the initial value and y-intercept are the same thing on a graph. is she correct? if you know that a line has a slope of and a y-intercept of 7, what is the equation for that line in slope-intercept form?